From 928b69f415d1f4331a89969d888140dba8109985 Mon Sep 17 00:00:00 2001
From: midzelis <min123@gmail.com>
Date: Mon, 3 Nov 2025 22:09:05 +0000
Subject: [PATCH] refactor(web): rename DayGroup/MonthGroup to
 TimelineDay/TimelineMonth
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

- Rename classes: DayGroup → TimelineDay, MonthGroup → TimelineMonth
- Use short variable names: dayGroup → day, monthGroup → month
- Update all method names and properties for consistency
- Convert relative imports to $lib alias convention

No functional changes.
---
 .../components/album-page/album-viewer.svelte |   2 +-
 .../lib/components/timeline/Scrubber.svelte   |  16 +-
 .../lib/components/timeline/Timeline.svelte   | 112 ++++++------
 .../timeline/TimelineAssetViewer.svelte       |   2 +-
 .../timeline/TimelineDateGroup.svelte         | 103 +++++------
 .../timeline/actions/SelectAllAction.svelte   |   2 +-
 .../actions/TimelineKeyboardActions.svelte    |   2 +-
 .../timeline/actions/focus-actions.ts         |   2 +-
 .../ScrollSegment.svelte.ts                   |   1 +
 ...-group.svelte.ts => TimelineDay.svelte.ts} |  34 ++--
 ...spec.ts => TimelineManager.svelte.spec.ts} | 132 +++++++--------
 ...er.svelte.ts => TimelineManager.svelte.ts} | 160 +++++++++---------
 ...roup.svelte.ts => TimelineMonth.svelte.ts} | 127 +++++++-------
 .../group-insertion-cache.svelte.ts           |  56 +++---
 .../internal/TestHooks.svelte.ts              |  12 +-
 .../internal/intersection-support.svelte.ts   |  20 +--
 .../internal/layout-support.svelte.ts         |  50 +++---
 .../internal/load-support.svelte.ts           |  16 +-
 .../internal/search-support.svelte.spec.ts    |  26 +--
 .../internal/search-support.svelte.ts         |  76 ++++-----
 .../internal/websocket-support.svelte.ts      |   2 +-
 .../managers/timeline-manager/utils.svelte.ts |   2 +-
 .../timeline-manager/viewer-asset.svelte.ts   |  17 +-
 web/src/lib/modals/NavigateToDateModal.svelte |   2 +-
 web/src/lib/utils/actions.ts                  |   2 +-
 web/src/lib/utils/asset-utils.ts              |  12 +-
 web/src/lib/utils/timeline-util.spec.ts       |  34 ++--
 web/src/lib/utils/timeline-util.ts            |   4 +-
 .../[[assetId=id]]/+page.svelte               |   4 +-
 .../[[assetId=id]]/+page.svelte               |   2 +-
 .../[[assetId=id]]/+page.svelte               |   2 +-
 .../[[assetId=id]]/+page.svelte               |   2 +-
 .../[[assetId=id]]/+page.svelte               |   2 +-
 .../(user)/photos/[[assetId=id]]/+page.svelte |   2 +-
 .../[[assetId=id]]/+page.svelte               |   2 +-
 .../[[assetId=id]]/+page.svelte               |   2 +-
 .../(user)/utilities/geolocation/+page.svelte |  10 +-
 37 files changed, 517 insertions(+), 537 deletions(-)
 create mode 100644 web/src/lib/managers/VirtualScrollManager/ScrollSegment.svelte.ts
 rename web/src/lib/managers/timeline-manager/{day-group.svelte.ts => TimelineDay.svelte.ts} (84%)
 rename web/src/lib/managers/timeline-manager/{timeline-manager.svelte.spec.ts => TimelineManager.svelte.spec.ts} (84%)
 rename web/src/lib/managers/timeline-manager/{timeline-manager.svelte.ts => TimelineManager.svelte.ts} (78%)
 rename web/src/lib/managers/timeline-manager/{month-group.svelte.ts => TimelineMonth.svelte.ts} (74%)

diff --git a/web/src/lib/components/album-page/album-viewer.svelte b/web/src/lib/components/album-page/album-viewer.svelte
index 8d169fbc8f..269bad1d23 100644
--- a/web/src/lib/components/album-page/album-viewer.svelte
+++ b/web/src/lib/components/album-page/album-viewer.svelte
@@ -6,7 +6,7 @@
   import SelectAllAssets from '$lib/components/timeline/actions/SelectAllAction.svelte';
   import AssetSelectControlBar from '$lib/components/timeline/AssetSelectControlBar.svelte';
   import Timeline from '$lib/components/timeline/Timeline.svelte';
-  import { TimelineManager } from '$lib/managers/timeline-manager/timeline-manager.svelte';
+  import { TimelineManager } from '$lib/managers/timeline-manager/TimelineManager.svelte';
   import { AssetInteraction } from '$lib/stores/asset-interaction.svelte';
   import { assetViewingStore } from '$lib/stores/asset-viewing.store';
   import { dragAndDropFilesStore } from '$lib/stores/drag-and-drop-files.store';
diff --git a/web/src/lib/components/timeline/Scrubber.svelte b/web/src/lib/components/timeline/Scrubber.svelte
index d64d45cc87..756aa4bbc1 100644
--- a/web/src/lib/components/timeline/Scrubber.svelte
+++ b/web/src/lib/components/timeline/Scrubber.svelte
@@ -1,5 +1,5 @@
 <script lang="ts">
-  import { TimelineManager } from '$lib/managers/timeline-manager/timeline-manager.svelte';
+  import { TimelineManager } from '$lib/managers/timeline-manager/TimelineManager.svelte';
   import type { ScrubberMonth, ViewportTopMonth } from '$lib/managers/timeline-manager/types';
   import { mobileDevice } from '$lib/stores/mobile-device.svelte';
   import { getTabbable } from '$lib/utils/focus-util';
@@ -91,7 +91,7 @@
     scrubberWidth = usingMobileDevice ? MOBILE_WIDTH : DESKTOP_WIDTH;
   });
 
-  const toScrollFromMonthGroupPercentage = (
+  const toScrollFromMonthPercentage = (
     scrubberMonth: ViewportTopMonth,
     scrubberMonthPercent: number,
     scrubOverallPercent: number,
@@ -124,7 +124,7 @@
     }
   };
   const scrollY = $derived(
-    toScrollFromMonthGroupPercentage(viewportTopMonth, viewportTopMonthScrollPercent, timelineScrollPercent),
+    toScrollFromMonthPercentage(viewportTopMonth, viewportTopMonthScrollPercent, timelineScrollPercent),
   );
   const timelineFullHeight = $derived(timelineManager.scrubberTimelineHeight);
   const relativeTopOffset = $derived(toScrollY(timelineTopOffset / timelineFullHeight));
@@ -280,12 +280,12 @@
       const boundingClientRect = bestElement.boundingClientRect;
       const sy = boundingClientRect.y;
       const relativeY = y - sy;
-      const monthGroupPercentY = relativeY / boundingClientRect.height;
+      const monthPercentY = relativeY / boundingClientRect.height;
       return {
         isOnPaddingTop: false,
         isOnPaddingBottom: false,
         segment,
-        monthGroupPercentY,
+        monthPercentY,
       };
     }
 
@@ -308,7 +308,7 @@
       isOnPaddingTop,
       isOnPaddingBottom,
       segment: undefined,
-      monthGroupPercentY: 0,
+      monthPercentY: 0,
     };
   };
 
@@ -327,7 +327,7 @@
     const upper = rect?.height - (PADDING_TOP + PADDING_BOTTOM);
     hoverY = clamp(clientY - rect?.top - PADDING_TOP, lower, upper);
     const x = rect!.left + rect!.width / 2;
-    const { segment, monthGroupPercentY, isOnPaddingTop, isOnPaddingBottom } = getActive(x, clientY);
+    const { segment, monthPercentY, isOnPaddingTop, isOnPaddingBottom } = getActive(x, clientY);
     activeSegment = segment;
     isHoverOnPaddingTop = isOnPaddingTop;
     isHoverOnPaddingBottom = isOnPaddingBottom;
@@ -335,7 +335,7 @@
     const scrubData = {
       scrubberMonth: segmentDate,
       overallScrollPercent: toTimelineY(hoverY),
-      scrubberMonthScrollPercent: monthGroupPercentY,
+      scrubberMonthScrollPercent: monthPercentY,
     };
     if (wasDragging === false && isDragging) {
       void startScrub?.(scrubData);
diff --git a/web/src/lib/components/timeline/Timeline.svelte b/web/src/lib/components/timeline/Timeline.svelte
index 044a45e725..e380b0b6c8 100644
--- a/web/src/lib/components/timeline/Timeline.svelte
+++ b/web/src/lib/components/timeline/Timeline.svelte
@@ -2,17 +2,17 @@
   import { afterNavigate, beforeNavigate } from '$app/navigation';
   import { page } from '$app/state';
   import { resizeObserver, type OnResizeCallback } from '$lib/actions/resize-observer';
+  import TimelineKeyboardActions from '$lib/components/timeline/actions/TimelineKeyboardActions.svelte';
   import Scrubber from '$lib/components/timeline/Scrubber.svelte';
   import TimelineAssetViewer from '$lib/components/timeline/TimelineAssetViewer.svelte';
-  import TimelineKeyboardActions from '$lib/components/timeline/actions/TimelineKeyboardActions.svelte';
   import { AssetAction } from '$lib/constants';
   import HotModuleReload from '$lib/elements/HotModuleReload.svelte';
   import Portal from '$lib/elements/Portal.svelte';
   import Skeleton from '$lib/elements/Skeleton.svelte';
-  import type { DayGroup } from '$lib/managers/timeline-manager/day-group.svelte';
   import { isIntersecting } from '$lib/managers/timeline-manager/internal/intersection-support.svelte';
-  import type { MonthGroup } from '$lib/managers/timeline-manager/month-group.svelte';
-  import { TimelineManager } from '$lib/managers/timeline-manager/timeline-manager.svelte';
+  import { TimelineDay } from '$lib/managers/timeline-manager/TimelineDay.svelte';
+  import { TimelineManager } from '$lib/managers/timeline-manager/TimelineManager.svelte';
+  import { TimelineMonth } from '$lib/managers/timeline-manager/TimelineMonth.svelte';
   import type { TimelineAsset, TimelineManagerOptions, ViewportTopMonth } from '$lib/managers/timeline-manager/types';
   import { assetsSnapshot } from '$lib/managers/timeline-manager/utils.svelte';
   import type { AssetInteraction } from '$lib/stores/asset-interaction.svelte';
@@ -58,11 +58,11 @@
     onThumbnailClick?: (
       asset: TimelineAsset,
       timelineManager: TimelineManager,
-      dayGroup: DayGroup,
+      day: TimelineDay,
       onClick: (
         timelineManager: TimelineManager,
         assets: TimelineAsset[],
-        groupTitle: string,
+        dayTitle: string,
         asset: TimelineAsset,
       ) => void,
     ) => void;
@@ -130,10 +130,10 @@
     timelineManager.scrollableElement = scrollableElement;
   });
 
-  const getAssetPosition = (assetId: string, monthGroup: MonthGroup) => monthGroup.findAssetAbsolutePosition(assetId);
+  const getAssetPosition = (assetId: string, month: TimelineMonth) => month.findAssetAbsolutePosition(assetId);
 
-  const scrollToAssetPosition = (assetId: string, monthGroup: MonthGroup) => {
-    const position = getAssetPosition(assetId, monthGroup);
+  const scrollToAssetPosition = (assetId: string, month: TimelineMonth) => {
+    const position = getAssetPosition(assetId, month);
 
     if (!position) {
       return;
@@ -176,20 +176,20 @@
   };
 
   const scrollAndLoadAsset = async (assetId: string) => {
-    const monthGroup = await timelineManager.findMonthGroupForAsset(assetId);
-    if (!monthGroup) {
+    const month = await timelineManager.findMonthForAsset(assetId);
+    if (!month) {
       return false;
     }
-    scrollToAssetPosition(assetId, monthGroup);
+    scrollToAssetPosition(assetId, month);
     return true;
   };
 
   const scrollToAsset = (asset: TimelineAsset) => {
-    const monthGroup = timelineManager.getMonthGroupByAssetId(asset.id);
-    if (!monthGroup) {
+    const month = timelineManager.getMonthByAssetId(asset.id);
+    if (!month) {
       return false;
     }
-    scrollToAssetPosition(asset.id, monthGroup);
+    scrollToAssetPosition(asset.id, month);
     return true;
   };
 
@@ -264,10 +264,10 @@
     }
   });
 
-  const scrollToSegmentPercentage = (segmentTop: number, segmentHeight: number, monthGroupScrollPercent: number) => {
+  const scrollToSegmentPercentage = (segmentTop: number, segmentHeight: number, monthScrollPercent: number) => {
     const topOffset = segmentTop;
     const maxScrollPercent = timelineManager.maxScrollPercent;
-    const delta = segmentHeight * monthGroupScrollPercent;
+    const delta = segmentHeight * monthScrollPercent;
     const scrollToTop = (topOffset + delta) * maxScrollPercent;
 
     timelineManager.scrollTo(scrollToTop);
@@ -296,13 +296,13 @@
         scrubberMonthScrollPercent,
       );
     } else {
-      const monthGroup = timelineManager.months.find(
+      const month = timelineManager.months.find(
         ({ yearMonth: { year, month } }) => year === scrubberMonth.year && month === scrubberMonth.month,
       );
-      if (!monthGroup) {
+      if (!month) {
         return;
       }
-      scrollToSegmentPercentage(monthGroup.top, monthGroup.height, scrubberMonthScrollPercent);
+      scrollToSegmentPercentage(month.top, month.height, scrubberMonthScrollPercent);
     }
   };
 
@@ -327,28 +327,28 @@
 
       const monthsLength = timelineManager.months.length;
       for (let i = -1; i < monthsLength + 1; i++) {
-        let monthGroup: ViewportTopMonth;
-        let monthGroupHeight = 0;
+        let month: ViewportTopMonth;
+        let monthHeight = 0;
         if (i === -1) {
           // lead-in
-          monthGroup = 'lead-in';
-          monthGroupHeight = timelineManager.topSectionHeight;
+          month = 'lead-in';
+          monthHeight = timelineManager.topSectionHeight;
         } else if (i === monthsLength) {
           // lead-out
-          monthGroup = 'lead-out';
-          monthGroupHeight = timelineManager.bottomSectionHeight;
+          month = 'lead-out';
+          monthHeight = timelineManager.bottomSectionHeight;
         } else {
-          monthGroup = timelineManager.months[i].yearMonth;
-          monthGroupHeight = timelineManager.months[i].height;
+          month = timelineManager.months[i].yearMonth;
+          monthHeight = timelineManager.months[i].height;
         }
 
-        let next = top - monthGroupHeight * maxScrollPercent;
+        let next = top - monthHeight * maxScrollPercent;
         // instead of checking for < 0, add a little wiggle room for subpixel resolution
-        if (next < -1 && monthGroup) {
-          viewportTopMonth = monthGroup;
+        if (next < -1 && month) {
+          viewportTopMonth = month;
 
           // allowing next to be at least 1 may cause percent to go negative, so ensure positive percentage
-          viewportTopMonthScrollPercent = Math.max(0, top / (monthGroupHeight * maxScrollPercent));
+          viewportTopMonthScrollPercent = Math.max(0, top / (monthHeight * maxScrollPercent));
 
           // compensate for lost precision/rounding errors advance to the next bucket, if present
           if (viewportTopMonthScrollPercent > 0.9999 && i + 1 < monthsLength - 1) {
@@ -442,8 +442,8 @@
     assetInteraction.clearAssetSelectionCandidates();
 
     if (assetInteraction.assetSelectionStart && rangeSelection) {
-      let startBucket = timelineManager.getMonthGroupByAssetId(assetInteraction.assetSelectionStart.id);
-      let endBucket = timelineManager.getMonthGroupByAssetId(asset.id);
+      let startBucket = timelineManager.getMonthByAssetId(assetInteraction.assetSelectionStart.id);
+      let endBucket = timelineManager.getMonthByAssetId(asset.id);
 
       if (startBucket === null || endBucket === null) {
         return;
@@ -451,13 +451,13 @@
 
       // Select/deselect assets in range (start,end)
       let started = false;
-      for (const monthGroup of timelineManager.months) {
-        if (monthGroup === endBucket) {
+      for (const month of timelineManager.months) {
+        if (month === endBucket) {
           break;
         }
         if (started) {
-          await timelineManager.loadMonthGroup(monthGroup.yearMonth);
-          for (const asset of monthGroup.assetsIterator()) {
+          await timelineManager.loadMonth(month.yearMonth);
+          for (const asset of month.assetsIterator()) {
             if (deselect) {
               assetInteraction.removeAssetFromMultiselectGroup(asset.id);
             } else {
@@ -465,29 +465,29 @@
             }
           }
         }
-        if (monthGroup === startBucket) {
+        if (month === startBucket) {
           started = true;
         }
       }
 
       // Update date group selection in range [start,end]
       started = false;
-      for (const monthGroup of timelineManager.months) {
-        if (monthGroup === startBucket) {
+      for (const month of timelineManager.months) {
+        if (month === startBucket) {
           started = true;
         }
         if (started) {
           // Split month group into day groups and check each group
-          for (const dayGroup of monthGroup.dayGroups) {
-            const dayGroupTitle = dayGroup.groupTitle;
-            if (dayGroup.getAssets().every((a) => assetInteraction.hasSelectedAsset(a.id))) {
-              assetInteraction.addGroupToMultiselectGroup(dayGroupTitle);
+          for (const day of month.days) {
+            const dayTitle = day.dayTitle;
+            if (day.getAssets().every((a) => assetInteraction.hasSelectedAsset(a.id))) {
+              assetInteraction.addGroupToMultiselectGroup(dayTitle);
             } else {
-              assetInteraction.removeGroupFromMultiselectGroup(dayGroupTitle);
+              assetInteraction.removeGroupFromMultiselectGroup(dayTitle);
             }
           }
         }
-        if (monthGroup === endBucket) {
+        if (month === endBucket) {
           break;
         }
       }
@@ -531,7 +531,7 @@
   $effect(() => {
     if ($showAssetViewer) {
       const { localDateTime } = getTimes($viewingAsset.fileCreatedAt, DateTime.local().offset / 60);
-      void timelineManager.loadMonthGroup({ year: localDateTime.year, month: localDateTime.month });
+      void timelineManager.loadMonth({ year: localDateTime.year, month: localDateTime.month });
     }
   });
 </script>
@@ -622,23 +622,23 @@
       {/if}
     </section>
 
-    {#each timelineManager.months as monthGroup (monthGroup.viewId)}
-      {@const display = monthGroup.intersecting}
-      {@const absoluteHeight = monthGroup.top}
+    {#each timelineManager.months as month (month.viewId)}
+      {@const display = month.intersecting}
+      {@const absoluteHeight = month.top}
 
-      {#if !monthGroup.isLoaded}
+      {#if !month.isLoaded}
         <div
-          style:height={monthGroup.height + 'px'}
+          style:height={month.height + 'px'}
           style:position="absolute"
           style:transform={`translate3d(0,${absoluteHeight}px,0)`}
           style:width="100%"
         >
-          <Skeleton {invisible} height={monthGroup.height} title={monthGroup.monthGroupTitle} />
+          <Skeleton {invisible} height={month.height} title={month.monthTitle} />
         </div>
       {:else if display}
         <div
           class="month-group"
-          style:height={monthGroup.height + 'px'}
+          style:height={month.height + 'px'}
           style:position="absolute"
           style:transform={`translate3d(0,${absoluteHeight}px,0)`}
           style:width="100%"
@@ -650,7 +650,7 @@
             {timelineManager}
             {isSelectionMode}
             {singleSelect}
-            {monthGroup}
+            {month}
             onSelect={({ title, assets }) => handleGroupSelect(timelineManager, title, assets)}
             onSelectAssetCandidates={handleSelectAssetCandidates}
             onSelectAssets={handleSelectAssets}
diff --git a/web/src/lib/components/timeline/TimelineAssetViewer.svelte b/web/src/lib/components/timeline/TimelineAssetViewer.svelte
index a121bd1938..43ab6a094f 100644
--- a/web/src/lib/components/timeline/TimelineAssetViewer.svelte
+++ b/web/src/lib/components/timeline/TimelineAssetViewer.svelte
@@ -2,7 +2,7 @@
   import type { Action } from '$lib/components/asset-viewer/actions/action';
   import { AssetAction } from '$lib/constants';
   import { authManager } from '$lib/managers/auth-manager.svelte';
-  import { TimelineManager } from '$lib/managers/timeline-manager/timeline-manager.svelte';
+  import { TimelineManager } from '$lib/managers/timeline-manager/TimelineManager.svelte';
   import { assetViewingStore } from '$lib/stores/asset-viewing.store';
   import { updateStackedAssetInTimeline, updateUnstackedAssetInTimeline } from '$lib/utils/actions';
   import { navigate } from '$lib/utils/navigation';
diff --git a/web/src/lib/components/timeline/TimelineDateGroup.svelte b/web/src/lib/components/timeline/TimelineDateGroup.svelte
index c662c16e72..a19ef4a118 100644
--- a/web/src/lib/components/timeline/TimelineDateGroup.svelte
+++ b/web/src/lib/components/timeline/TimelineDateGroup.svelte
@@ -1,19 +1,17 @@
 <script lang="ts">
   import Thumbnail from '$lib/components/assets/thumbnail/thumbnail.svelte';
-  import type { DayGroup } from '$lib/managers/timeline-manager/day-group.svelte';
-  import type { MonthGroup } from '$lib/managers/timeline-manager/month-group.svelte';
-  import { TimelineManager } from '$lib/managers/timeline-manager/timeline-manager.svelte';
+  import { TimelineDay } from '$lib/managers/timeline-manager/TimelineDay.svelte';
+  import { TimelineManager } from '$lib/managers/timeline-manager/TimelineManager.svelte';
+  import { TimelineMonth } from '$lib/managers/timeline-manager/TimelineMonth.svelte';
   import type { TimelineAsset } from '$lib/managers/timeline-manager/types';
   import { assetSnapshot, assetsSnapshot } from '$lib/managers/timeline-manager/utils.svelte';
   import type { AssetInteraction } from '$lib/stores/asset-interaction.svelte';
   import { isSelectingAllAssets } from '$lib/stores/assets-store.svelte';
   import { uploadAssetsStore } from '$lib/stores/upload';
   import { navigate } from '$lib/utils/navigation';
-
-  import { mdiCheckCircle, mdiCircleOutline } from '@mdi/js';
-
   import { fromTimelinePlainDate, getDateLocaleString } from '$lib/utils/timeline-util';
   import { Icon } from '@immich/ui';
+  import { mdiCheckCircle, mdiCircleOutline } from '@mdi/js';
   import { type Snippet } from 'svelte';
   import { flip } from 'svelte/animate';
   import { scale } from 'svelte/transition';
@@ -25,7 +23,7 @@
     singleSelect: boolean;
     withStacked: boolean;
     showArchiveIcon: boolean;
-    monthGroup: MonthGroup;
+    month: TimelineMonth;
     timelineManager: TimelineManager;
     assetInteraction: AssetInteraction;
     customLayout?: Snippet<[TimelineAsset]>;
@@ -36,11 +34,11 @@
     onThumbnailClick?: (
       asset: TimelineAsset,
       timelineManager: TimelineManager,
-      dayGroup: DayGroup,
+      day: TimelineDay,
       onClick: (
         timelineManager: TimelineManager,
         assets: TimelineAsset[],
-        groupTitle: string,
+        dayTitle: string,
         asset: TimelineAsset,
       ) => void,
     ) => void;
@@ -51,7 +49,7 @@
     singleSelect,
     withStacked,
     showArchiveIcon,
-    monthGroup = $bindable(),
+    month = $bindable(),
     assetInteraction,
     timelineManager,
     customLayout,
@@ -63,20 +61,18 @@
   }: Props = $props();
 
   let isMouseOverGroup = $state(false);
-  let hoveredDayGroup = $state();
+  let hoveredDay = $state();
 
-  const transitionDuration = $derived.by(() =>
-    monthGroup.timelineManager.suspendTransitions && !$isUploading ? 0 : 150,
-  );
+  const transitionDuration = $derived.by(() => (month.timelineManager.suspendTransitions && !$isUploading ? 0 : 150));
   const scaleDuration = $derived(transitionDuration === 0 ? 0 : transitionDuration + 100);
   const _onClick = (
     timelineManager: TimelineManager,
     assets: TimelineAsset[],
-    groupTitle: string,
+    dayTitle: string,
     asset: TimelineAsset,
   ) => {
     if (isSelectionMode || assetInteraction.selectionActive) {
-      assetSelectHandler(timelineManager, asset, assets, groupTitle);
+      assetSelectHandler(timelineManager, asset, assets, dayTitle);
       return;
     }
     void navigate({ targetRoute: 'current', assetId: asset.id });
@@ -87,21 +83,19 @@
   const assetSelectHandler = (
     timelineManager: TimelineManager,
     asset: TimelineAsset,
-    assetsInDayGroup: TimelineAsset[],
-    groupTitle: string,
+    assetsInDay: TimelineAsset[],
+    dayTitle: string,
   ) => {
     onSelectAssets(asset);
 
     // Check if all assets are selected in a group to toggle the group selection's icon
-    let selectedAssetsInGroupCount = assetsInDayGroup.filter((asset) =>
-      assetInteraction.hasSelectedAsset(asset.id),
-    ).length;
+    let selectedAssetsInDayCount = assetsInDay.filter((asset) => assetInteraction.hasSelectedAsset(asset.id)).length;
 
     // if all assets are selected in a group, add the group to selected group
-    if (selectedAssetsInGroupCount == assetsInDayGroup.length) {
-      assetInteraction.addGroupToMultiselectGroup(groupTitle);
+    if (selectedAssetsInDayCount == assetsInDay.length) {
+      assetInteraction.addGroupToMultiselectGroup(dayTitle);
     } else {
-      assetInteraction.removeGroupFromMultiselectGroup(groupTitle);
+      assetInteraction.removeGroupFromMultiselectGroup(dayTitle);
     }
 
     if (timelineManager.assetCount == assetInteraction.selectedAssets.length) {
@@ -111,9 +105,9 @@
     }
   };
 
-  const assetMouseEventHandler = (groupTitle: string, asset: TimelineAsset | null) => {
+  const assetMouseEventHandler = (dayTitle: string, asset: TimelineAsset | null) => {
     // Show multi select icon on hover on date group
-    hoveredDayGroup = groupTitle;
+    hoveredDay = dayTitle;
 
     if (assetInteraction.selectionActive) {
       onSelectAssetCandidates(asset);
@@ -124,52 +118,52 @@
     return intersectable.filter((int) => int.intersecting);
   }
 
-  const getDayGroupFullDate = (dayGroup: DayGroup): string => {
-    const { month, year } = dayGroup.monthGroup.yearMonth;
+  const getDayFullDate = (day: TimelineDay): string => {
+    const { month, year } = day.month.yearMonth;
     const date = fromTimelinePlainDate({
       year,
       month,
-      day: dayGroup.day,
+      day: day.day,
     });
     return getDateLocaleString(date);
   };
 </script>
 
-{#each filterIntersecting(monthGroup.dayGroups) as dayGroup, groupIndex (dayGroup.day)}
-  {@const absoluteWidth = dayGroup.left}
+{#each filterIntersecting(month.days) as day, groupIndex (day.day)}
+  {@const absoluteWidth = day.left}
 
   <!-- svelte-ignore a11y_no_static_element_interactions -->
   <section
     class={[
-      { 'transition-all': !monthGroup.timelineManager.suspendTransitions },
-      !monthGroup.timelineManager.suspendTransitions && `delay-${transitionDuration}`,
+      { 'transition-all': !month.timelineManager.suspendTransitions },
+      !month.timelineManager.suspendTransitions && `delay-${transitionDuration}`,
     ]}
     data-group
     style:position="absolute"
-    style:transform={`translate3d(${absoluteWidth}px,${dayGroup.top}px,0)`}
+    style:transform={`translate3d(${absoluteWidth}px,${day.top}px,0)`}
     onmouseenter={() => {
       isMouseOverGroup = true;
-      assetMouseEventHandler(dayGroup.groupTitle, null);
+      assetMouseEventHandler(day.dayTitle, null);
     }}
     onmouseleave={() => {
       isMouseOverGroup = false;
-      assetMouseEventHandler(dayGroup.groupTitle, null);
+      assetMouseEventHandler(day.dayTitle, null);
     }}
   >
     <!-- Date group title -->
     <div
       class="flex pt-7 pb-5 max-md:pt-5 max-md:pb-3 h-6 place-items-center text-xs font-medium text-immich-fg dark:text-immich-dark-fg md:text-sm"
-      style:width={dayGroup.width + 'px'}
+      style:width={day.width + 'px'}
     >
       {#if !singleSelect}
         <div
           class="hover:cursor-pointer transition-all duration-200 ease-out overflow-hidden w-0"
-          class:w-8={(hoveredDayGroup === dayGroup.groupTitle && isMouseOverGroup) ||
-            assetInteraction.selectedGroup.has(dayGroup.groupTitle)}
-          onclick={() => handleSelectGroup(dayGroup.groupTitle, assetsSnapshot(dayGroup.getAssets()))}
-          onkeydown={() => handleSelectGroup(dayGroup.groupTitle, assetsSnapshot(dayGroup.getAssets()))}
+          class:w-8={(hoveredDay === day.dayTitle && isMouseOverGroup) ||
+            assetInteraction.selectedGroup.has(day.dayTitle)}
+          onclick={() => handleSelectGroup(day.dayTitle, assetsSnapshot(day.getAssets()))}
+          onkeydown={() => handleSelectGroup(day.dayTitle, assetsSnapshot(day.getAssets()))}
         >
-          {#if assetInteraction.selectedGroup.has(dayGroup.groupTitle)}
+          {#if assetInteraction.selectedGroup.has(day.dayTitle)}
             <Icon icon={mdiCheckCircle} size="24" class="text-primary" />
           {:else}
             <Icon icon={mdiCircleOutline} size="24" color="#757575" />
@@ -177,19 +171,14 @@
         </div>
       {/if}
 
-      <span class="w-full truncate first-letter:capitalize" title={getDayGroupFullDate(dayGroup)}>
-        {dayGroup.groupTitle}
+      <span class="w-full truncate first-letter:capitalize" title={getDayFullDate(day)}>
+        {day.dayTitle}
       </span>
     </div>
 
     <!-- Image grid -->
-    <div
-      data-image-grid
-      class="relative overflow-clip"
-      style:height={dayGroup.height + 'px'}
-      style:width={dayGroup.width + 'px'}
-    >
-      {#each filterIntersecting(dayGroup.viewerAssets) as viewerAsset (viewerAsset.id)}
+    <div data-image-grid class="relative overflow-clip" style:height={day.height + 'px'} style:width={day.width + 'px'}>
+      {#each filterIntersecting(day.viewerAssets) as viewerAsset (viewerAsset.id)}
         {@const position = viewerAsset.position!}
         {@const asset = viewerAsset.asset!}
 
@@ -212,17 +201,17 @@
             {groupIndex}
             onClick={(asset) => {
               if (typeof onThumbnailClick === 'function') {
-                onThumbnailClick(asset, timelineManager, dayGroup, _onClick);
+                onThumbnailClick(asset, timelineManager, day, _onClick);
               } else {
-                _onClick(timelineManager, dayGroup.getAssets(), dayGroup.groupTitle, asset);
+                _onClick(timelineManager, day.getAssets(), day.dayTitle, asset);
               }
             }}
-            onSelect={(asset) => assetSelectHandler(timelineManager, asset, dayGroup.getAssets(), dayGroup.groupTitle)}
-            onMouseEvent={() => assetMouseEventHandler(dayGroup.groupTitle, assetSnapshot(asset))}
+            onSelect={(asset) => assetSelectHandler(timelineManager, asset, day.getAssets(), day.dayTitle)}
+            onMouseEvent={() => assetMouseEventHandler(day.dayTitle, assetSnapshot(asset))}
             selected={assetInteraction.hasSelectedAsset(asset.id) ||
-              dayGroup.monthGroup.timelineManager.albumAssets.has(asset.id)}
+              day.month.timelineManager.albumAssets.has(asset.id)}
             selectionCandidate={assetInteraction.hasSelectionCandidate(asset.id)}
-            disabled={dayGroup.monthGroup.timelineManager.albumAssets.has(asset.id)}
+            disabled={day.month.timelineManager.albumAssets.has(asset.id)}
             thumbnailWidth={position.width}
             thumbnailHeight={position.height}
           />
diff --git a/web/src/lib/components/timeline/actions/SelectAllAction.svelte b/web/src/lib/components/timeline/actions/SelectAllAction.svelte
index 883ec1d54e..7cd64fccda 100644
--- a/web/src/lib/components/timeline/actions/SelectAllAction.svelte
+++ b/web/src/lib/components/timeline/actions/SelectAllAction.svelte
@@ -1,5 +1,5 @@
 <script lang="ts">
-  import { TimelineManager } from '$lib/managers/timeline-manager/timeline-manager.svelte';
+  import { TimelineManager } from '$lib/managers/timeline-manager/TimelineManager.svelte';
   import type { AssetInteraction } from '$lib/stores/asset-interaction.svelte';
   import { isSelectingAllAssets } from '$lib/stores/assets-store.svelte';
   import { cancelMultiselect, selectAllAssets } from '$lib/utils/asset-utils';
diff --git a/web/src/lib/components/timeline/actions/TimelineKeyboardActions.svelte b/web/src/lib/components/timeline/actions/TimelineKeyboardActions.svelte
index ad9921e47a..9e452e2406 100644
--- a/web/src/lib/components/timeline/actions/TimelineKeyboardActions.svelte
+++ b/web/src/lib/components/timeline/actions/TimelineKeyboardActions.svelte
@@ -7,7 +7,7 @@
     setFocusTo as setFocusToInit,
   } from '$lib/components/timeline/actions/focus-actions';
   import { AppRoute } from '$lib/constants';
-  import { TimelineManager } from '$lib/managers/timeline-manager/timeline-manager.svelte';
+  import { TimelineManager } from '$lib/managers/timeline-manager/TimelineManager.svelte';
   import type { TimelineAsset } from '$lib/managers/timeline-manager/types';
   import NavigateToDateModal from '$lib/modals/NavigateToDateModal.svelte';
   import ShortcutsModal from '$lib/modals/ShortcutsModal.svelte';
diff --git a/web/src/lib/components/timeline/actions/focus-actions.ts b/web/src/lib/components/timeline/actions/focus-actions.ts
index f0f9e2e50c..22cf536954 100644
--- a/web/src/lib/components/timeline/actions/focus-actions.ts
+++ b/web/src/lib/components/timeline/actions/focus-actions.ts
@@ -1,4 +1,4 @@
-import { TimelineManager } from '$lib/managers/timeline-manager/timeline-manager.svelte';
+import { TimelineManager } from '$lib/managers/timeline-manager/TimelineManager.svelte';
 import type { TimelineAsset } from '$lib/managers/timeline-manager/types';
 import { moveFocus } from '$lib/utils/focus-util';
 import { InvocationTracker } from '$lib/utils/invocationTracker';
diff --git a/web/src/lib/managers/VirtualScrollManager/ScrollSegment.svelte.ts b/web/src/lib/managers/VirtualScrollManager/ScrollSegment.svelte.ts
new file mode 100644
index 0000000000..2244712bf9
--- /dev/null
+++ b/web/src/lib/managers/VirtualScrollManager/ScrollSegment.svelte.ts
@@ -0,0 +1 @@
+export class ScrollSegment {}
diff --git a/web/src/lib/managers/timeline-manager/day-group.svelte.ts b/web/src/lib/managers/timeline-manager/TimelineDay.svelte.ts
similarity index 84%
rename from web/src/lib/managers/timeline-manager/day-group.svelte.ts
rename to web/src/lib/managers/timeline-manager/TimelineDay.svelte.ts
index 3a05c0664f..aa1291686f 100644
--- a/web/src/lib/managers/timeline-manager/day-group.svelte.ts
+++ b/web/src/lib/managers/timeline-manager/TimelineDay.svelte.ts
@@ -1,18 +1,16 @@
-import { AssetOrder } from '@immich/sdk';
-
+import { onCreateDay } from '$lib/managers/timeline-manager/internal/TestHooks.svelte';
+import { TimelineMonth } from '$lib/managers/timeline-manager/TimelineMonth.svelte';
+import type { AssetOperation, Direction, TimelineAsset } from '$lib/managers/timeline-manager/types';
+import { ViewerAsset } from '$lib/managers/timeline-manager/viewer-asset.svelte';
 import type { CommonLayoutOptions } from '$lib/utils/layout-utils';
 import { getJustifiedLayoutFromAssets } from '$lib/utils/layout-utils';
 import { plainDateTimeCompare } from '$lib/utils/timeline-util';
+import { AssetOrder } from '@immich/sdk';
 
-import { onCreateDayGroup } from '$lib/managers/timeline-manager/internal/TestHooks.svelte';
-import type { MonthGroup } from './month-group.svelte';
-import type { AssetOperation, Direction, TimelineAsset } from './types';
-import { ViewerAsset } from './viewer-asset.svelte';
-
-export class DayGroup {
-  readonly monthGroup: MonthGroup;
+export class TimelineDay {
+  readonly month: TimelineMonth;
   readonly index: number;
-  readonly groupTitle: string;
+  readonly dayTitle: string;
   readonly day: number;
   viewerAssets: ViewerAsset[] = $state([]);
 
@@ -26,13 +24,13 @@ export class DayGroup {
   #col = $state(0);
   #deferredLayout = false;
 
-  constructor(monthGroup: MonthGroup, index: number, day: number, groupTitle: string) {
+  constructor(month: TimelineMonth, index: number, day: number, dayTitle: string) {
     this.index = index;
-    this.monthGroup = monthGroup;
+    this.month = month;
     this.day = day;
-    this.groupTitle = groupTitle;
+    this.dayTitle = dayTitle;
     if (import.meta.env.DEV) {
-      onCreateDayGroup(this);
+      onCreateDay(this);
     }
   }
 
@@ -144,7 +142,7 @@ export class DayGroup {
       }
       unprocessedIds.delete(assetId);
       processedIds.add(assetId);
-      if (remove || this.monthGroup.timelineManager.isExcluded(asset)) {
+      if (remove || this.month.timelineManager.isExcluded(asset)) {
         this.viewerAssets.splice(index, 1);
         changedGeometry = true;
       }
@@ -153,7 +151,7 @@ export class DayGroup {
   }
 
   layout(options: CommonLayoutOptions, noDefer: boolean) {
-    if (!noDefer && !this.monthGroup.intersecting) {
+    if (!noDefer && !this.month.intersecting) {
       this.#deferredLayout = true;
       return;
     }
@@ -167,7 +165,7 @@ export class DayGroup {
     }
   }
 
-  get absoluteDayGroupTop() {
-    return this.monthGroup.top + this.#top;
+  get absoluteTop() {
+    return this.month.top + this.#top;
   }
 }
diff --git a/web/src/lib/managers/timeline-manager/timeline-manager.svelte.spec.ts b/web/src/lib/managers/timeline-manager/TimelineManager.svelte.spec.ts
similarity index 84%
rename from web/src/lib/managers/timeline-manager/timeline-manager.svelte.spec.ts
rename to web/src/lib/managers/timeline-manager/TimelineManager.svelte.spec.ts
index cbfce5c829..bf1b54e63d 100644
--- a/web/src/lib/managers/timeline-manager/timeline-manager.svelte.spec.ts
+++ b/web/src/lib/managers/timeline-manager/TimelineManager.svelte.spec.ts
@@ -1,16 +1,16 @@
 import { sdkMock } from '$lib/__mocks__/sdk.mock';
-import type { DayGroup } from '$lib/managers/timeline-manager/day-group.svelte';
-import { getMonthGroupByDate } from '$lib/managers/timeline-manager/internal/search-support.svelte';
+import { getMonthByDate } from '$lib/managers/timeline-manager/internal/search-support.svelte';
 import { setTestHooks } from '$lib/managers/timeline-manager/internal/TestHooks.svelte';
-import type { MonthGroup } from '$lib/managers/timeline-manager/month-group.svelte';
+import { TimelineDay } from '$lib/managers/timeline-manager/TimelineDay.svelte';
+import { TimelineManager } from '$lib/managers/timeline-manager/TimelineManager.svelte';
+import { TimelineMonth } from '$lib/managers/timeline-manager/TimelineMonth.svelte';
+import type { TimelineAsset } from '$lib/managers/timeline-manager/types';
 import { AbortError } from '$lib/utils';
 import { fromISODateTimeUTCToObject } from '$lib/utils/timeline-util';
 import { AssetVisibility, type AssetResponseDto, type TimeBucketAssetResponseDto } from '@immich/sdk';
 import { timelineAssetFactory, toResponseDto } from '@test-data/factories/asset-factory';
 import { tick } from 'svelte';
 import type { MockInstance } from 'vitest';
-import { TimelineManager } from './timeline-manager.svelte';
-import type { TimelineAsset } from './types';
 
 async function getAssets(timelineManager: TimelineManager) {
   const assets = [];
@@ -98,7 +98,7 @@ describe('TimelineManager', () => {
     });
   });
 
-  describe('loadMonthGroup', () => {
+  describe('loadMonth', () => {
     let timelineManager: TimelineManager;
     const bucketAssets: Record<string, TimelineAsset[]> = {
       '2024-01-03T00:00:00.000Z': timelineAssetFactory.buildList(1).map((asset) =>
@@ -134,47 +134,47 @@ describe('TimelineManager', () => {
     });
 
     it('loads a month', async () => {
-      expect(getMonthGroupByDate(timelineManager, { year: 2024, month: 1 })?.getAssets().length).toEqual(0);
-      await timelineManager.loadMonthGroup({ year: 2024, month: 1 });
+      expect(getMonthByDate(timelineManager, { year: 2024, month: 1 })?.getAssets().length).toEqual(0);
+      await timelineManager.loadMonth({ year: 2024, month: 1 });
       expect(sdkMock.getTimeBucket).toBeCalledTimes(1);
-      expect(getMonthGroupByDate(timelineManager, { year: 2024, month: 1 })?.getAssets().length).toEqual(3);
+      expect(getMonthByDate(timelineManager, { year: 2024, month: 1 })?.getAssets().length).toEqual(3);
     });
 
     it('ignores invalid months', async () => {
-      await timelineManager.loadMonthGroup({ year: 2023, month: 1 });
+      await timelineManager.loadMonth({ year: 2023, month: 1 });
       expect(sdkMock.getTimeBucket).toBeCalledTimes(0);
     });
 
     it('cancels month loading', async () => {
-      const month = getMonthGroupByDate(timelineManager, { year: 2024, month: 1 })!;
-      void timelineManager.loadMonthGroup({ year: 2024, month: 1 });
+      const month = getMonthByDate(timelineManager, { year: 2024, month: 1 })!;
+      void timelineManager.loadMonth({ year: 2024, month: 1 });
       const abortSpy = vi.spyOn(month!.loader!.cancelToken!, 'abort');
       month?.cancel();
       expect(abortSpy).toBeCalledTimes(1);
-      await timelineManager.loadMonthGroup({ year: 2024, month: 1 });
-      expect(getMonthGroupByDate(timelineManager, { year: 2024, month: 1 })?.getAssets().length).toEqual(3);
+      await timelineManager.loadMonth({ year: 2024, month: 1 });
+      expect(getMonthByDate(timelineManager, { year: 2024, month: 1 })?.getAssets().length).toEqual(3);
     });
 
     it('prevents loading months multiple times', async () => {
       await Promise.all([
-        timelineManager.loadMonthGroup({ year: 2024, month: 1 }),
-        timelineManager.loadMonthGroup({ year: 2024, month: 1 }),
+        timelineManager.loadMonth({ year: 2024, month: 1 }),
+        timelineManager.loadMonth({ year: 2024, month: 1 }),
       ]);
       expect(sdkMock.getTimeBucket).toBeCalledTimes(1);
 
-      await timelineManager.loadMonthGroup({ year: 2024, month: 1 });
+      await timelineManager.loadMonth({ year: 2024, month: 1 });
       expect(sdkMock.getTimeBucket).toBeCalledTimes(1);
     });
 
     it('allows loading a canceled month', async () => {
-      const month = getMonthGroupByDate(timelineManager, { year: 2024, month: 1 })!;
-      const loadPromise = timelineManager.loadMonthGroup({ year: 2024, month: 1 });
+      const month = getMonthByDate(timelineManager, { year: 2024, month: 1 })!;
+      const loadPromise = timelineManager.loadMonth({ year: 2024, month: 1 });
 
       month.cancel();
       await loadPromise;
       expect(month?.getAssets().length).toEqual(0);
 
-      await timelineManager.loadMonthGroup({ year: 2024, month: 1 });
+      await timelineManager.loadMonth({ year: 2024, month: 1 });
       expect(month!.getAssets().length).toEqual(3);
     });
   });
@@ -244,7 +244,7 @@ describe('TimelineManager', () => {
       );
       timelineManager.upsertAssets([assetOne, assetTwo, assetThree]);
 
-      const month = getMonthGroupByDate(timelineManager, { year: 2024, month: 1 });
+      const month = getMonthByDate(timelineManager, { year: 2024, month: 1 });
       expect(month).not.toBeNull();
       expect(month?.getAssets().length).toEqual(3);
       expect(month?.getAssets()[0].id).toEqual(assetOne.id);
@@ -319,24 +319,24 @@ describe('TimelineManager', () => {
       sortAssetsFn: MockInstance;
     };
     type MonthMocks = {
-      sortDayGroupsFn: MockInstance;
+      sortDaysFn: MockInstance;
     };
 
-    const dayGroups = new Map<DayGroup, DayMocks>();
-    const monthGroups = new Map<MonthGroup, MonthMocks>();
+    const days = new Map<TimelineDay, DayMocks>();
+    const months = new Map<TimelineMonth, MonthMocks>();
 
     beforeEach(async () => {
       timelineManager = new TimelineManager();
       setTestHooks({
-        onCreateDayGroup: (dayGroup: DayGroup) => {
-          dayGroups.set(dayGroup, {
-            layoutFn: vi.spyOn(dayGroup, 'layout'),
-            sortAssetsFn: vi.spyOn(dayGroup, 'sortAssets'),
+        onCreateDay: (day: TimelineDay) => {
+          days.set(day, {
+            layoutFn: vi.spyOn(day, 'layout'),
+            sortAssetsFn: vi.spyOn(day, 'sortAssets'),
           });
         },
-        onCreateMonthGroup: (monthGroup: MonthGroup) => {
-          monthGroups.set(monthGroup, {
-            sortDayGroupsFn: vi.spyOn(monthGroup, 'sortDayGroups'),
+        onCreateMonth: (month: TimelineMonth) => {
+          months.set(month, {
+            sortDaysFn: vi.spyOn(month, 'sortDays'),
           });
         },
       });
@@ -394,13 +394,13 @@ describe('TimelineManager', () => {
       timelineManager.updateAssetOperation([month1day2asset1.id], (asset) => {
         asset.localDateTime.day = asset.localDateTime.day + 1;
       });
-      for (const [day, mocks] of dayGroups) {
-        if (day.day === 15 && day.monthGroup.yearMonth.month === 1) {
+      for (const [day, mocks] of days) {
+        if (day.day === 15 && day.month.yearMonth.month === 1) {
           // source - should be layout once
           expect.soft(mocks.layoutFn).toBeCalledTimes(1);
           expect.soft(mocks.sortAssetsFn).toBeCalledTimes(1);
         }
-        if (day.day === 16 && day.monthGroup.yearMonth.month === 1) {
+        if (day.day === 16 && day.month.yearMonth.month === 1) {
           // target - should be layout once
           expect.soft(mocks.layoutFn).toBeCalledTimes(1);
           expect.soft(mocks.sortAssetsFn).toBeCalledTimes(1);
@@ -409,12 +409,12 @@ describe('TimelineManager', () => {
         expect.soft(mocks.layoutFn).toBeCalledTimes(0);
         expect.soft(mocks.sortAssetsFn).toBeCalledTimes(0);
       }
-      for (const [_, mocks] of monthGroups) {
+      for (const [_, mocks] of months) {
         // if the day itself did not change, probably no need to sort it
         // in the timeline manager, the day-group identity is immutable - you will never
         // "move" a whole day to another day - only the assets inside will be moved from
         // one to the other.
-        expect.soft(mocks.sortDayGroupsFn).toBeCalledTimes(0);
+        expect.soft(mocks.sortDaysFn).toBeCalledTimes(0);
       }
     });
   });
@@ -455,15 +455,15 @@ describe('TimelineManager', () => {
 
       timelineManager.upsertAssets([asset]);
       expect(timelineManager.months.length).toEqual(1);
-      expect(getMonthGroupByDate(timelineManager, { year: 2024, month: 1 })).not.toBeUndefined();
-      expect(getMonthGroupByDate(timelineManager, { year: 2024, month: 1 })?.getAssets().length).toEqual(1);
+      expect(getMonthByDate(timelineManager, { year: 2024, month: 1 })).not.toBeUndefined();
+      expect(getMonthByDate(timelineManager, { year: 2024, month: 1 })?.getAssets().length).toEqual(1);
 
       timelineManager.upsertAssets([updatedAsset]);
       expect(timelineManager.months.length).toEqual(2);
-      expect(getMonthGroupByDate(timelineManager, { year: 2024, month: 1 })).not.toBeUndefined();
-      expect(getMonthGroupByDate(timelineManager, { year: 2024, month: 1 })?.getAssets().length).toEqual(0);
-      expect(getMonthGroupByDate(timelineManager, { year: 2024, month: 3 })).not.toBeUndefined();
-      expect(getMonthGroupByDate(timelineManager, { year: 2024, month: 3 })?.getAssets().length).toEqual(1);
+      expect(getMonthByDate(timelineManager, { year: 2024, month: 1 })).not.toBeUndefined();
+      expect(getMonthByDate(timelineManager, { year: 2024, month: 1 })?.getAssets().length).toEqual(0);
+      expect(getMonthByDate(timelineManager, { year: 2024, month: 3 })).not.toBeUndefined();
+      expect(getMonthByDate(timelineManager, { year: 2024, month: 3 })?.getAssets().length).toEqual(1);
     });
 
     it('asset is removed during upsert when TimelineManager if visibility changes', async () => {
@@ -655,8 +655,8 @@ describe('TimelineManager', () => {
     });
 
     it('returns previous assetId', async () => {
-      await timelineManager.loadMonthGroup({ year: 2024, month: 1 });
-      const month = getMonthGroupByDate(timelineManager, { year: 2024, month: 1 });
+      await timelineManager.loadMonth({ year: 2024, month: 1 });
+      const month = getMonthByDate(timelineManager, { year: 2024, month: 1 });
 
       const a = month!.getAssets()[0];
       const b = month!.getAssets()[1];
@@ -665,11 +665,11 @@ describe('TimelineManager', () => {
     });
 
     it('returns previous assetId spanning multiple months', async () => {
-      await timelineManager.loadMonthGroup({ year: 2024, month: 2 });
-      await timelineManager.loadMonthGroup({ year: 2024, month: 3 });
+      await timelineManager.loadMonth({ year: 2024, month: 2 });
+      await timelineManager.loadMonth({ year: 2024, month: 3 });
 
-      const month = getMonthGroupByDate(timelineManager, { year: 2024, month: 2 });
-      const previousMonth = getMonthGroupByDate(timelineManager, { year: 2024, month: 3 });
+      const month = getMonthByDate(timelineManager, { year: 2024, month: 2 });
+      const previousMonth = getMonthByDate(timelineManager, { year: 2024, month: 3 });
       const a = month!.getAssets()[0];
       const b = previousMonth!.getAssets()[0];
       const previous = await timelineManager.getLaterAsset(a);
@@ -677,23 +677,23 @@ describe('TimelineManager', () => {
     });
 
     it('loads previous month', async () => {
-      await timelineManager.loadMonthGroup({ year: 2024, month: 2 });
-      const month = getMonthGroupByDate(timelineManager, { year: 2024, month: 2 });
-      const previousMonth = getMonthGroupByDate(timelineManager, { year: 2024, month: 3 });
+      await timelineManager.loadMonth({ year: 2024, month: 2 });
+      const month = getMonthByDate(timelineManager, { year: 2024, month: 2 });
+      const previousMonth = getMonthByDate(timelineManager, { year: 2024, month: 3 });
       const a = month!.getFirstAsset();
       const b = previousMonth!.getFirstAsset();
-      const loadMonthGroupSpy = vi.spyOn(month!.loader!, 'execute');
+      const loadMonthSpy = vi.spyOn(month!.loader!, 'execute');
       const previousMonthSpy = vi.spyOn(previousMonth!.loader!, 'execute');
       const previous = await timelineManager.getLaterAsset(a);
       expect(previous).toEqual(b);
-      expect(loadMonthGroupSpy).toBeCalledTimes(0);
+      expect(loadMonthSpy).toBeCalledTimes(0);
       expect(previousMonthSpy).toBeCalledTimes(0);
     });
 
     it('skips removed assets', async () => {
-      await timelineManager.loadMonthGroup({ year: 2024, month: 1 });
-      await timelineManager.loadMonthGroup({ year: 2024, month: 2 });
-      await timelineManager.loadMonthGroup({ year: 2024, month: 3 });
+      await timelineManager.loadMonth({ year: 2024, month: 1 });
+      await timelineManager.loadMonth({ year: 2024, month: 2 });
+      await timelineManager.loadMonth({ year: 2024, month: 3 });
 
       const [assetOne, assetTwo, assetThree] = await getAssets(timelineManager);
       timelineManager.removeAssets([assetTwo.id]);
@@ -701,12 +701,12 @@ describe('TimelineManager', () => {
     });
 
     it('returns null when no more assets', async () => {
-      await timelineManager.loadMonthGroup({ year: 2024, month: 3 });
+      await timelineManager.loadMonth({ year: 2024, month: 3 });
       expect(await timelineManager.getLaterAsset(timelineManager.months[0].getFirstAsset())).toBeUndefined();
     });
   });
 
-  describe('getMonthGroupIndexByAssetId', () => {
+  describe('getMonthIndexByAssetId', () => {
     let timelineManager: TimelineManager;
 
     beforeEach(async () => {
@@ -717,8 +717,8 @@ describe('TimelineManager', () => {
     });
 
     it('returns null for invalid months', () => {
-      expect(getMonthGroupByDate(timelineManager, { year: -1, month: -1 })).toBeUndefined();
-      expect(getMonthGroupByDate(timelineManager, { year: 2024, month: 3 })).toBeUndefined();
+      expect(getMonthByDate(timelineManager, { year: -1, month: -1 })).toBeUndefined();
+      expect(getMonthByDate(timelineManager, { year: 2024, month: 3 })).toBeUndefined();
     });
 
     it('returns the month index', () => {
@@ -734,10 +734,10 @@ describe('TimelineManager', () => {
       );
       timelineManager.upsertAssets([assetOne, assetTwo]);
 
-      expect(timelineManager.getMonthGroupByAssetId(assetTwo.id)?.yearMonth.year).toEqual(2024);
-      expect(timelineManager.getMonthGroupByAssetId(assetTwo.id)?.yearMonth.month).toEqual(2);
-      expect(timelineManager.getMonthGroupByAssetId(assetOne.id)?.yearMonth.year).toEqual(2024);
-      expect(timelineManager.getMonthGroupByAssetId(assetOne.id)?.yearMonth.month).toEqual(1);
+      expect(timelineManager.getMonthByAssetId(assetTwo.id)?.yearMonth.year).toEqual(2024);
+      expect(timelineManager.getMonthByAssetId(assetTwo.id)?.yearMonth.month).toEqual(2);
+      expect(timelineManager.getMonthByAssetId(assetOne.id)?.yearMonth.year).toEqual(2024);
+      expect(timelineManager.getMonthByAssetId(assetOne.id)?.yearMonth.month).toEqual(1);
     });
 
     it('ignores removed months', () => {
@@ -754,8 +754,8 @@ describe('TimelineManager', () => {
       timelineManager.upsertAssets([assetOne, assetTwo]);
 
       timelineManager.removeAssets([assetTwo.id]);
-      expect(timelineManager.getMonthGroupByAssetId(assetOne.id)?.yearMonth.year).toEqual(2024);
-      expect(timelineManager.getMonthGroupByAssetId(assetOne.id)?.yearMonth.month).toEqual(1);
+      expect(timelineManager.getMonthByAssetId(assetOne.id)?.yearMonth.year).toEqual(2024);
+      expect(timelineManager.getMonthByAssetId(assetOne.id)?.yearMonth.month).toEqual(1);
     });
   });
 
diff --git a/web/src/lib/managers/timeline-manager/timeline-manager.svelte.ts b/web/src/lib/managers/timeline-manager/TimelineManager.svelte.ts
similarity index 78%
rename from web/src/lib/managers/timeline-manager/timeline-manager.svelte.ts
rename to web/src/lib/managers/timeline-manager/TimelineManager.svelte.ts
index 70e89d29cd..46713d2cfa 100644
--- a/web/src/lib/managers/timeline-manager/timeline-manager.svelte.ts
+++ b/web/src/lib/managers/timeline-manager/TimelineManager.svelte.ts
@@ -1,18 +1,30 @@
 import { VirtualScrollManager } from '$lib/managers/VirtualScrollManager/VirtualScrollManager.svelte';
 import { authManager } from '$lib/managers/auth-manager.svelte';
+import { TimelineDay } from '$lib/managers/timeline-manager/TimelineDay.svelte';
+import { TimelineMonth } from '$lib/managers/timeline-manager/TimelineMonth.svelte';
 import { GroupInsertionCache } from '$lib/managers/timeline-manager/group-insertion-cache.svelte';
-import { updateIntersectionMonthGroup } from '$lib/managers/timeline-manager/internal/intersection-support.svelte';
+import { updateIntersectionMonth } from '$lib/managers/timeline-manager/internal/intersection-support.svelte';
 import { updateGeometry } from '$lib/managers/timeline-manager/internal/layout-support.svelte';
 import { loadFromTimeBuckets } from '$lib/managers/timeline-manager/internal/load-support.svelte';
 import {
   findClosestGroupForDate,
-  findMonthGroupForAsset as findMonthGroupForAssetUtil,
-  findMonthGroupForDate,
+  findMonthForAsset as findMonthForAssetUtil,
+  findMonthForDate,
   getAssetWithOffset,
-  getMonthGroupByDate,
+  getMonthByDate,
   retrieveRange as retrieveRangeUtil,
 } from '$lib/managers/timeline-manager/internal/search-support.svelte';
+import { isMismatched, updateObject } from '$lib/managers/timeline-manager/internal/utils.svelte';
 import { WebsocketSupport } from '$lib/managers/timeline-manager/internal/websocket-support.svelte';
+import type {
+  AssetDescriptor,
+  AssetOperation,
+  Direction,
+  ScrubberMonth,
+  TimelineAsset,
+  TimelineManagerOptions,
+  Viewport,
+} from '$lib/managers/timeline-manager/types';
 import { CancellableTask } from '$lib/utils/cancellable-task';
 import {
   setDifferenceInPlace,
@@ -23,21 +35,9 @@ import {
 import { AssetOrder, getAssetInfo, getTimeBuckets } from '@immich/sdk';
 import { clamp, isEqual } from 'lodash-es';
 import { SvelteDate, SvelteSet } from 'svelte/reactivity';
-import { DayGroup } from './day-group.svelte';
-import { isMismatched, updateObject } from './internal/utils.svelte';
-import { MonthGroup } from './month-group.svelte';
-import type {
-  AssetDescriptor,
-  AssetOperation,
-  Direction,
-  ScrubberMonth,
-  TimelineAsset,
-  TimelineManagerOptions,
-  Viewport,
-} from './types';
 
 type ViewportTopMonthIntersection = {
-  month: MonthGroup | undefined;
+  month: TimelineMonth | undefined;
   // Where viewport top intersects month (0 = month top, 1 = month bottom)
   viewportTopRatioInMonth: number;
   // Where month bottom is in viewport (0 = viewport top, 1 = viewport bottom)
@@ -63,7 +63,7 @@ export class TimelineManager extends VirtualScrollManager {
   });
 
   isInitialized = $state(false);
-  months: MonthGroup[] = $state([]);
+  months: TimelineMonth[] = $state([]);
   albumAssets: Set<string> = new SvelteSet();
   scrubberMonths: ScrubberMonth[] = $state([]);
   scrubberTimelineHeight: number = $state(0);
@@ -113,24 +113,24 @@ export class TimelineManager extends VirtualScrollManager {
   }
 
   async *assetsIterator(options?: {
-    startMonthGroup?: MonthGroup;
-    startDayGroup?: DayGroup;
+    startMonth?: TimelineMonth;
+    startDay?: TimelineDay;
     startAsset?: TimelineAsset;
     direction?: Direction;
   }) {
     const direction = options?.direction ?? 'earlier';
-    let { startDayGroup, startAsset } = options ?? {};
-    for (const monthGroup of this.monthGroupIterator({ direction, startMonthGroup: options?.startMonthGroup })) {
-      await this.loadMonthGroup(monthGroup.yearMonth, { cancelable: false });
-      yield* monthGroup.assetsIterator({ startDayGroup, startAsset, direction });
-      startDayGroup = startAsset = undefined;
+    let { startDay, startAsset } = options ?? {};
+    for (const month of this.monthIterator({ direction, startMonth: options?.startMonth })) {
+      await this.loadMonth(month.yearMonth, { cancelable: false });
+      yield* month.assetsIterator({ startDay, startAsset, direction });
+      startDay = startAsset = undefined;
     }
   }
 
-  *monthGroupIterator(options?: { direction?: Direction; startMonthGroup?: MonthGroup }) {
+  *monthIterator(options?: { direction?: Direction; startMonth?: TimelineMonth }) {
     const isEarlier = options?.direction === 'earlier';
-    let startIndex = options?.startMonthGroup
-      ? this.months.indexOf(options.startMonthGroup)
+    let startIndex = options?.startMonth
+      ? this.months.indexOf(options.startMonth)
       : isEarlier
         ? 0
         : this.months.length - 1;
@@ -157,7 +157,7 @@ export class TimelineManager extends VirtualScrollManager {
     this.#websocketSupport = undefined;
   }
 
-  #calculateMonthBottomViewportRatio(month: MonthGroup | undefined) {
+  #calculateMonthBottomViewportRatio(month: TimelineMonth | undefined) {
     if (!month) {
       return 0;
     }
@@ -167,7 +167,7 @@ export class TimelineManager extends VirtualScrollManager {
     return clamp(bottomOfMonthInViewport / windowHeight, 0, 1);
   }
 
-  #calculateVewportTopRatioInMonth(month: MonthGroup | undefined) {
+  #calculateVewportTopRatioInMonth(month: TimelineMonth | undefined) {
     if (!month) {
       return 0;
     }
@@ -181,7 +181,7 @@ export class TimelineManager extends VirtualScrollManager {
     this.#updatingIntersections = true;
 
     for (const month of this.months) {
-      updateIntersectionMonthGroup(this, month);
+      updateIntersectionMonth(this, month);
     }
 
     const month = this.months.find((month) => month.actuallyIntersecting);
@@ -197,17 +197,17 @@ export class TimelineManager extends VirtualScrollManager {
     this.#updatingIntersections = false;
   }
 
-  clearDeferredLayout(month: MonthGroup) {
-    const hasDeferred = month.dayGroups.some((group) => group.deferredLayout);
+  clearDeferredLayout(month: TimelineMonth) {
+    const hasDeferred = month.days.some((group) => group.deferredLayout);
     if (hasDeferred) {
       updateGeometry(this, month, { invalidateHeight: true, noDefer: true });
-      for (const group of month.dayGroups) {
+      for (const group of month.days) {
         group.deferredLayout = false;
       }
     }
   }
 
-  async #initializeMonthGroups() {
+  async #initializeMonths() {
     const timebuckets = await getTimeBuckets({
       ...authManager.params,
       ...this.#options,
@@ -215,7 +215,7 @@ export class TimelineManager extends VirtualScrollManager {
 
     this.months = timebuckets.map((timeBucket) => {
       const date = new SvelteDate(timeBucket.timeBucket);
-      return new MonthGroup(
+      return new TimelineMonth(
         this,
         { year: date.getUTCFullYear(), month: date.getUTCMonth() + 1 },
         timeBucket.count,
@@ -246,7 +246,7 @@ export class TimelineManager extends VirtualScrollManager {
     this.albumAssets.clear();
     await this.initTask.execute(async () => {
       this.#options = options;
-      await this.#initializeMonthGroups();
+      await this.#initializeMonths();
     }, true);
   }
 
@@ -293,31 +293,31 @@ export class TimelineManager extends VirtualScrollManager {
       assetCount: month.assetsCount,
       year: month.yearMonth.year,
       month: month.yearMonth.month,
-      title: month.monthGroupTitle,
+      title: month.monthTitle,
       height: month.height,
     }));
     this.scrubberTimelineHeight = this.totalViewerHeight;
   }
 
-  async loadMonthGroup(yearMonth: TimelineYearMonth, options?: { cancelable: boolean }): Promise<void> {
+  async loadMonth(yearMonth: TimelineYearMonth, options?: { cancelable: boolean }): Promise<void> {
     let cancelable = true;
     if (options) {
       cancelable = options.cancelable;
     }
-    const monthGroup = getMonthGroupByDate(this, yearMonth);
-    if (!monthGroup) {
+    const month = getMonthByDate(this, yearMonth);
+    if (!month) {
       return;
     }
 
-    if (monthGroup.loader?.executed) {
+    if (month.loader?.executed) {
       return;
     }
 
-    const executionStatus = await monthGroup.loader?.execute(async (signal: AbortSignal) => {
-      await loadFromTimeBuckets(this, monthGroup, this.#options, signal);
+    const executionStatus = await month.loader?.execute(async (signal: AbortSignal) => {
+      await loadFromTimeBuckets(this, month, this.#options, signal);
     }, cancelable);
     if (executionStatus === 'LOADED') {
-      updateGeometry(this, monthGroup, { invalidateHeight: false });
+      updateGeometry(this, month, { invalidateHeight: false });
       this.updateIntersections();
     }
   }
@@ -328,14 +328,14 @@ export class TimelineManager extends VirtualScrollManager {
     this.addAssetsToSegments(notExcluded);
   }
 
-  async findMonthGroupForAsset(id: string) {
+  async findMonthForAsset(id: string) {
     if (!this.isInitialized) {
       await this.initTask.waitUntilCompletion();
     }
 
-    let { monthGroup } = findMonthGroupForAssetUtil(this, id) ?? {};
-    if (monthGroup) {
-      return monthGroup;
+    let { month } = findMonthForAssetUtil(this, id) ?? {};
+    if (month) {
+      return month;
     }
 
     const response = await getAssetInfo({ ...authManager.params, id }).catch(() => null);
@@ -348,20 +348,20 @@ export class TimelineManager extends VirtualScrollManager {
       return;
     }
 
-    monthGroup = await this.#loadMonthGroupAtTime(asset.localDateTime, { cancelable: false });
-    if (monthGroup?.findAssetById({ id })) {
-      return monthGroup;
+    month = await this.#loadMonthAtTime(asset.localDateTime, { cancelable: false });
+    if (month?.findAssetById({ id })) {
+      return month;
     }
   }
 
-  async #loadMonthGroupAtTime(yearMonth: TimelineYearMonth, options?: { cancelable: boolean }) {
-    await this.loadMonthGroup(yearMonth, options);
-    return getMonthGroupByDate(this, yearMonth);
+  async #loadMonthAtTime(yearMonth: TimelineYearMonth, options?: { cancelable: boolean }) {
+    await this.loadMonth(yearMonth, options);
+    return getMonthByDate(this, yearMonth);
   }
 
-  getMonthGroupByAssetId(assetId: string) {
-    const monthGroupInfo = findMonthGroupForAssetUtil(this, assetId);
-    return monthGroupInfo?.monthGroup;
+  getMonthByAssetId(assetId: string) {
+    const monthInfo = findMonthForAssetUtil(this, assetId);
+    return monthInfo?.month;
   }
 
   // note: the `index` input is expected to be in the range [0, assetCount). This
@@ -372,7 +372,7 @@ export class TimelineManager extends VirtualScrollManager {
 
     let accumulatedCount = 0;
 
-    let randomMonth: MonthGroup | undefined = undefined;
+    let randomMonth: TimelineMonth | undefined = undefined;
     for (const month of this.months) {
       if (randomAssetIndex < accumulatedCount + month.assetsCount) {
         randomMonth = month;
@@ -384,10 +384,10 @@ export class TimelineManager extends VirtualScrollManager {
     if (!randomMonth) {
       return;
     }
-    await this.loadMonthGroup(randomMonth.yearMonth, { cancelable: false });
+    await this.loadMonth(randomMonth.yearMonth, { cancelable: false });
 
-    let randomDay: DayGroup | undefined = undefined;
-    for (const day of randomMonth.dayGroups) {
+    let randomDay: TimelineDay | undefined = undefined;
+    for (const day of randomMonth.days) {
       if (randomAssetIndex < accumulatedCount + day.viewerAssets.length) {
         randomDay = day;
         break;
@@ -443,10 +443,10 @@ export class TimelineManager extends VirtualScrollManager {
   }
 
   protected upsertAssetIntoSegment(asset: TimelineAsset, context: GroupInsertionCache): void {
-    let month = getMonthGroupByDate(this, asset.localDateTime);
+    let month = getMonthByDate(this, asset.localDateTime);
 
     if (!month) {
-      month = new MonthGroup(this, asset.localDateTime, 1, true, this.#options.order);
+      month = new TimelineMonth(this, asset.localDateTime, 1, true, this.#options.order);
       this.months.push(month);
     }
 
@@ -476,7 +476,7 @@ export class TimelineManager extends VirtualScrollManager {
     }
 
     // eslint-disable-next-line svelte/prefer-svelte-reactivity
-    const changedMonthGroups = new Set<MonthGroup>();
+    const changedMonths = new Set<TimelineMonth>();
     // eslint-disable-next-line svelte/prefer-svelte-reactivity
     const idsToProcess = new Set(ids);
     // eslint-disable-next-line svelte/prefer-svelte-reactivity
@@ -493,15 +493,15 @@ export class TimelineManager extends VirtualScrollManager {
           idsProcessed.add(id);
         }
         if (changedGeometry) {
-          changedMonthGroups.add(month);
+          changedMonths.add(month);
         }
       }
     }
     if (combinedMoveAssets.length > 0) {
       this.addAssetsToSegments(combinedMoveAssets);
     }
-    const changedGeometry = changedMonthGroups.size > 0;
-    for (const month of changedMonthGroups) {
+    const changedGeometry = changedMonths.size > 0;
+    for (const month of changedMonths) {
       updateGeometry(this, month, { invalidateHeight: true });
     }
     if (changedGeometry) {
@@ -536,20 +536,20 @@ export class TimelineManager extends VirtualScrollManager {
   }
 
   async getClosestAssetToDate(dateTime: TimelineDateTime) {
-    let monthGroup = findMonthGroupForDate(this, dateTime);
-    if (!monthGroup) {
+    let month = findMonthForDate(this, dateTime);
+    if (!month) {
       // if exact match not found, find closest
-      monthGroup = findClosestGroupForDate(this.months, dateTime);
-      if (!monthGroup) {
+      month = findClosestGroupForDate(this.months, dateTime);
+      if (!month) {
         return;
       }
     }
-    await this.loadMonthGroup(dateTime, { cancelable: false });
-    const asset = monthGroup.findClosest(dateTime);
+    await this.loadMonth(dateTime, { cancelable: false });
+    const asset = month.findClosest(dateTime);
     if (asset) {
       return asset;
     }
-    for await (const asset of this.assetsIterator({ startMonthGroup: monthGroup })) {
+    for await (const asset of this.assetsIterator({ startMonth: month })) {
       return asset;
     }
   }
@@ -579,16 +579,16 @@ export class TimelineManager extends VirtualScrollManager {
   }
 
   protected postUpsert(context: GroupInsertionCache): void {
-    for (const group of context.existingDayGroups) {
+    for (const group of context.existingDays) {
       group.sortAssets(this.#options.order);
     }
 
-    for (const monthGroup of context.bucketsWithNewDayGroups) {
-      monthGroup.sortDayGroups();
+    for (const month of context.monthsWithNewDays) {
+      month.sortDays();
     }
 
-    for (const month of context.updatedBuckets) {
-      month.sortDayGroups();
+    for (const month of context.updatedMonths) {
+      month.sortDays();
       updateGeometry(this, month, { invalidateHeight: true });
     }
   }
diff --git a/web/src/lib/managers/timeline-manager/month-group.svelte.ts b/web/src/lib/managers/timeline-manager/TimelineMonth.svelte.ts
similarity index 74%
rename from web/src/lib/managers/timeline-manager/month-group.svelte.ts
rename to web/src/lib/managers/timeline-manager/TimelineMonth.svelte.ts
index f4edf6111b..91990aaf1b 100644
--- a/web/src/lib/managers/timeline-manager/month-group.svelte.ts
+++ b/web/src/lib/managers/timeline-manager/TimelineMonth.svelte.ts
@@ -1,10 +1,15 @@
-import { AssetOrder, type TimeBucketAssetResponseDto } from '@immich/sdk';
-
+import { GroupInsertionCache } from '$lib/managers/timeline-manager/group-insertion-cache.svelte';
+import { onCreateMonth } from '$lib/managers/timeline-manager/internal/TestHooks.svelte';
+import { TimelineDay } from '$lib/managers/timeline-manager/TimelineDay.svelte';
+import { TimelineManager } from '$lib/managers/timeline-manager/TimelineManager.svelte';
+import type { AssetDescriptor, AssetOperation, Direction, TimelineAsset } from '$lib/managers/timeline-manager/types';
+import { ViewerAsset } from '$lib/managers/timeline-manager/viewer-asset.svelte';
+import { ScrollSegment } from '$lib/managers/VirtualScrollManager/ScrollSegment.svelte';
 import { CancellableTask } from '$lib/utils/cancellable-task';
 import { handleError } from '$lib/utils/handle-error';
 import {
-  formatGroupTitle,
-  formatMonthGroupTitle,
+  formatDayTitle,
+  formatMonthTitle,
   fromTimelinePlainDate,
   fromTimelinePlainDateTime,
   fromTimelinePlainYearMonth,
@@ -13,22 +18,15 @@ import {
   type TimelineDateTime,
   type TimelineYearMonth,
 } from '$lib/utils/timeline-util';
-
+import { AssetOrder, type TimeBucketAssetResponseDto } from '@immich/sdk';
 import { t } from 'svelte-i18n';
 import { get } from 'svelte/store';
 
-import { onCreateMonthGroup } from '$lib/managers/timeline-manager/internal/TestHooks.svelte';
-import { DayGroup } from './day-group.svelte';
-import { GroupInsertionCache } from './group-insertion-cache.svelte';
-import { TimelineManager } from './timeline-manager.svelte';
-import type { AssetDescriptor, AssetOperation, Direction, TimelineAsset } from './types';
-import { ViewerAsset } from './viewer-asset.svelte';
-
-export class MonthGroup {
+export class TimelineMonth extends ScrollSegment {
   #intersecting: boolean = $state(false);
   actuallyIntersecting: boolean = $state(false);
   isLoaded: boolean = $state(false);
-  dayGroups: DayGroup[] = $state([]);
+  days: TimelineDay[] = $state([]);
   readonly timelineManager: TimelineManager;
 
   #height: number = $state(0);
@@ -39,14 +37,12 @@ export class MonthGroup {
   percent: number = $state(0);
 
   assetsCount: number = $derived(
-    this.isLoaded
-      ? this.dayGroups.reduce((accumulator, g) => accumulator + g.viewerAssets.length, 0)
-      : this.#initialCount,
+    this.isLoaded ? this.days.reduce((accumulator, g) => accumulator + g.viewerAssets.length, 0) : this.#initialCount,
   );
   loader: CancellableTask | undefined;
   isHeightActual: boolean = $state(false);
 
-  readonly monthGroupTitle: string;
+  readonly monthTitle: string;
   readonly yearMonth: TimelineYearMonth;
 
   constructor(
@@ -56,19 +52,20 @@ export class MonthGroup {
     loaded: boolean,
     order: AssetOrder = AssetOrder.Desc,
   ) {
+    super();
     this.timelineManager = timelineManager;
     this.#initialCount = initialCount;
     this.#sortOrder = order;
 
     this.yearMonth = yearMonth;
-    this.monthGroupTitle = formatMonthGroupTitle(fromTimelinePlainYearMonth(yearMonth));
+    this.monthTitle = formatMonthTitle(fromTimelinePlainYearMonth(yearMonth));
 
     this.loader = new CancellableTask(
       () => {
         this.isLoaded = true;
       },
       () => {
-        this.dayGroups = [];
+        this.days = [];
         this.isLoaded = false;
       },
       this.#handleLoadError,
@@ -77,7 +74,7 @@ export class MonthGroup {
       this.isLoaded = true;
     }
     if (import.meta.env.DEV) {
-      onCreateMonthGroup(this);
+      onCreateMonth(this);
     }
   }
 
@@ -88,7 +85,7 @@ export class MonthGroup {
     }
     this.#intersecting = newValue;
     if (newValue) {
-      void this.timelineManager.loadMonthGroup(this.yearMonth);
+      void this.timelineManager.loadMonth(this.yearMonth);
     } else {
       this.cancel();
     }
@@ -98,25 +95,25 @@ export class MonthGroup {
     return this.#intersecting;
   }
 
-  get lastDayGroup() {
-    return this.dayGroups.at(-1);
+  get lastDay() {
+    return this.days.at(-1);
   }
 
   getFirstAsset() {
-    return this.dayGroups[0]?.getFirstAsset();
+    return this.days[0]?.getFirstAsset();
   }
 
   getAssets() {
     // eslint-disable-next-line unicorn/no-array-reduce
-    return this.dayGroups.reduce((accumulator: TimelineAsset[], g: DayGroup) => accumulator.concat(g.getAssets()), []);
+    return this.days.reduce((accumulator: TimelineAsset[], g: TimelineDay) => accumulator.concat(g.getAssets()), []);
   }
 
-  sortDayGroups() {
+  sortDays() {
     if (this.#sortOrder === AssetOrder.Asc) {
-      return this.dayGroups.sort((a, b) => a.day - b.day);
+      return this.days.sort((a, b) => a.day - b.day);
     }
 
-    return this.dayGroups.sort((a, b) => b.day - a.day);
+    return this.days.sort((a, b) => b.day - a.day);
   }
 
   runAssetOperation(ids: Set<string>, operation: AssetOperation) {
@@ -129,17 +126,17 @@ export class MonthGroup {
         changedGeometry: false,
       };
     }
-    const { dayGroups } = this;
+    const { days } = this;
     let combinedChangedGeometry = false;
     // eslint-disable-next-line svelte/prefer-svelte-reactivity
     const idsToProcess = new Set(ids);
     // eslint-disable-next-line svelte/prefer-svelte-reactivity
     const idsProcessed = new Set<string>();
     const combinedMoveAssets: TimelineAsset[] = [];
-    let index = dayGroups.length;
+    let index = days.length;
     while (index--) {
       if (idsToProcess.size > 0) {
-        const group = dayGroups[index];
+        const group = days[index];
         const { moveAssets, processedIds, changedGeometry } = group.runAssetOperation(ids, operation);
         if (moveAssets.length > 0) {
           combinedMoveAssets.push(...moveAssets);
@@ -150,7 +147,7 @@ export class MonthGroup {
         }
         combinedChangedGeometry = combinedChangedGeometry || changedGeometry;
         if (group.viewerAssets.length === 0) {
-          dayGroups.splice(index, 1);
+          days.splice(index, 1);
           combinedChangedGeometry = true;
         }
       }
@@ -205,12 +202,12 @@ export class MonthGroup {
       this.addTimelineAsset(timelineAsset, addContext);
     }
     if (!preSorted) {
-      for (const group of addContext.existingDayGroups) {
+      for (const group of addContext.existingDays) {
         group.sortAssets(this.#sortOrder);
       }
 
-      if (addContext.newDayGroups.size > 0) {
-        this.sortDayGroups();
+      if (addContext.newDays.size > 0) {
+        this.sortDays();
       }
 
       addContext.sort(this, this.#sortOrder);
@@ -227,20 +224,20 @@ export class MonthGroup {
       return;
     }
 
-    let dayGroup = addContext.getDayGroup(localDateTime) || this.findDayGroupByDay(localDateTime.day);
-    if (dayGroup) {
-      addContext.setDayGroup(dayGroup, localDateTime);
+    let day = addContext.getDay(localDateTime) || this.findDayByDay(localDateTime.day);
+    if (day) {
+      addContext.setDay(day, localDateTime);
     } else {
-      const groupTitle = formatGroupTitle(fromTimelinePlainDate(localDateTime));
-      dayGroup = new DayGroup(this, this.dayGroups.length, localDateTime.day, groupTitle);
-      this.dayGroups.push(dayGroup);
-      addContext.setDayGroup(dayGroup, localDateTime);
-      addContext.newDayGroups.add(dayGroup);
+      const dayTitle = formatDayTitle(fromTimelinePlainDate(localDateTime));
+      day = new TimelineDay(this, this.days.length, localDateTime.day, dayTitle);
+      this.days.push(day);
+      addContext.setDay(day, localDateTime);
+      addContext.newDays.add(day);
     }
 
-    const viewerAsset = new ViewerAsset(dayGroup, timelineAsset);
-    dayGroup.viewerAssets.push(viewerAsset);
-    addContext.changedDayGroups.add(dayGroup);
+    const viewerAsset = new ViewerAsset(day, timelineAsset);
+    day.viewerAssets.push(viewerAsset);
+    addContext.changedDays.add(day);
   }
 
   get viewId() {
@@ -256,9 +253,9 @@ export class MonthGroup {
     const index = timelineManager.months.indexOf(this);
     const heightDelta = height - this.#height;
     this.#height = height;
-    const prevMonthGroup = timelineManager.months[index - 1];
-    if (prevMonthGroup) {
-      const newTop = prevMonthGroup.#top + prevMonthGroup.#height;
+    const prevMonth = timelineManager.months[index - 1];
+    if (prevMonth) {
+      const newTop = prevMonth.#top + prevMonth.#height;
       if (this.#top !== newTop) {
         this.#top = newTop;
       }
@@ -267,10 +264,10 @@ export class MonthGroup {
       return;
     }
     for (let cursor = index + 1; cursor < timelineManager.months.length; cursor++) {
-      const monthGroup = this.timelineManager.months[cursor];
-      const newTop = monthGroup.#top + heightDelta;
-      if (monthGroup.#top !== newTop) {
-        monthGroup.#top = newTop;
+      const month = this.timelineManager.months[cursor];
+      const newTop = month.#top + heightDelta;
+      if (month.#top !== newTop) {
+        month.#top = newTop;
       }
     }
     if (!timelineManager.viewportTopMonthIntersection) {
@@ -302,21 +299,21 @@ export class MonthGroup {
     handleError(error, _$t('errors.failed_to_load_assets'));
   }
 
-  findDayGroupForAsset(asset: TimelineAsset) {
-    for (const group of this.dayGroups) {
+  findDayForAsset(asset: TimelineAsset) {
+    for (const group of this.days) {
       if (group.viewerAssets.some((viewerAsset) => viewerAsset.id === asset.id)) {
         return group;
       }
     }
   }
 
-  findDayGroupByDay(day: number) {
-    return this.dayGroups.find((group) => group.day === day);
+  findDayByDay(day: number) {
+    return this.days.find((group) => group.day === day);
   }
 
   findAssetAbsolutePosition(assetId: string) {
     this.timelineManager.clearDeferredLayout(this);
-    for (const group of this.dayGroups) {
+    for (const group of this.days) {
       const viewerAsset = group.viewerAssets.find((viewAsset) => viewAsset.id === assetId);
       if (viewerAsset) {
         if (!viewerAsset.position) {
@@ -331,18 +328,14 @@ export class MonthGroup {
     }
   }
 
-  *assetsIterator(options?: { startDayGroup?: DayGroup; startAsset?: TimelineAsset; direction?: Direction }) {
+  *assetsIterator(options?: { startDay?: TimelineDay; startAsset?: TimelineAsset; direction?: Direction }) {
     const direction = options?.direction ?? 'earlier';
     let { startAsset } = options ?? {};
     const isEarlier = direction === 'earlier';
-    let groupIndex = options?.startDayGroup
-      ? this.dayGroups.indexOf(options.startDayGroup)
-      : isEarlier
-        ? 0
-        : this.dayGroups.length - 1;
+    let groupIndex = options?.startDay ? this.days.indexOf(options.startDay) : isEarlier ? 0 : this.days.length - 1;
 
-    while (groupIndex >= 0 && groupIndex < this.dayGroups.length) {
-      const group = this.dayGroups[groupIndex];
+    while (groupIndex >= 0 && groupIndex < this.days.length) {
+      const group = this.days[groupIndex];
       yield* group.assetsIterator({ startAsset, direction });
       startAsset = undefined;
       groupIndex += isEarlier ? 1 : -1;
diff --git a/web/src/lib/managers/timeline-manager/group-insertion-cache.svelte.ts b/web/src/lib/managers/timeline-manager/group-insertion-cache.svelte.ts
index 566b11b8b7..68c3c79add 100644
--- a/web/src/lib/managers/timeline-manager/group-insertion-cache.svelte.ts
+++ b/web/src/lib/managers/timeline-manager/group-insertion-cache.svelte.ts
@@ -1,64 +1,64 @@
+import { TimelineDay } from '$lib/managers/timeline-manager/TimelineDay.svelte';
+import { TimelineMonth } from '$lib/managers/timeline-manager/TimelineMonth.svelte';
+import type { TimelineAsset } from '$lib/managers/timeline-manager/types';
 import { setDifference, type TimelineDate } from '$lib/utils/timeline-util';
 import { AssetOrder } from '@immich/sdk';
-import type { DayGroup } from './day-group.svelte';
-import type { MonthGroup } from './month-group.svelte';
-import type { TimelineAsset } from './types';
 
 export class GroupInsertionCache {
   #lookupCache: {
-    [year: number]: { [month: number]: { [day: number]: DayGroup } };
+    [year: number]: { [month: number]: { [day: number]: TimelineDay } };
   } = {};
   unprocessedAssets: TimelineAsset[] = [];
   // eslint-disable-next-line svelte/prefer-svelte-reactivity
-  changedDayGroups = new Set<DayGroup>();
+  changedDays = new Set<TimelineDay>();
   // eslint-disable-next-line svelte/prefer-svelte-reactivity
-  newDayGroups = new Set<DayGroup>();
+  newDays = new Set<TimelineDay>();
 
-  getDayGroup({ year, month, day }: TimelineDate): DayGroup | undefined {
+  getDay({ year, month, day }: TimelineDate): TimelineDay | undefined {
     return this.#lookupCache[year]?.[month]?.[day];
   }
 
-  setDayGroup(dayGroup: DayGroup, { year, month, day }: TimelineDate) {
+  setDay(day: TimelineDay, { year, month, day: dayNumber }: TimelineDate) {
     if (!this.#lookupCache[year]) {
       this.#lookupCache[year] = {};
     }
     if (!this.#lookupCache[year][month]) {
       this.#lookupCache[year][month] = {};
     }
-    this.#lookupCache[year][month][day] = dayGroup;
+    this.#lookupCache[year][month][dayNumber] = day;
   }
 
-  get existingDayGroups() {
-    return setDifference(this.changedDayGroups, this.newDayGroups);
+  get existingDays() {
+    return setDifference(this.changedDays, this.newDays);
   }
 
-  get updatedBuckets() {
+  get updatedMonths() {
     // eslint-disable-next-line svelte/prefer-svelte-reactivity
-    const updated = new Set<MonthGroup>();
-    for (const group of this.changedDayGroups) {
-      updated.add(group.monthGroup);
+    const months = new Set<TimelineMonth>();
+    for (const day of this.changedDays) {
+      months.add(day.month);
     }
-    return updated;
+    return months;
   }
 
-  get bucketsWithNewDayGroups() {
+  get monthsWithNewDays() {
     // eslint-disable-next-line svelte/prefer-svelte-reactivity
-    const updated = new Set<MonthGroup>();
-    for (const group of this.newDayGroups) {
-      updated.add(group.monthGroup);
+    const months = new Set<TimelineMonth>();
+    for (const day of this.newDays) {
+      months.add(day.month);
     }
-    return updated;
+    return months;
   }
 
-  sort(monthGroup: MonthGroup, sortOrder: AssetOrder = AssetOrder.Desc) {
-    for (const group of this.changedDayGroups) {
-      group.sortAssets(sortOrder);
+  sort(month: TimelineMonth, sortOrder: AssetOrder = AssetOrder.Desc) {
+    for (const day of this.changedDays) {
+      day.sortAssets(sortOrder);
     }
-    for (const group of this.newDayGroups) {
-      group.sortAssets(sortOrder);
+    for (const day of this.newDays) {
+      day.sortAssets(sortOrder);
     }
-    if (this.newDayGroups.size > 0) {
-      monthGroup.sortDayGroups();
+    if (this.newDays.size > 0) {
+      month.sortDays();
     }
   }
 }
diff --git a/web/src/lib/managers/timeline-manager/internal/TestHooks.svelte.ts b/web/src/lib/managers/timeline-manager/internal/TestHooks.svelte.ts
index 9de90cbda0..486726ea56 100644
--- a/web/src/lib/managers/timeline-manager/internal/TestHooks.svelte.ts
+++ b/web/src/lib/managers/timeline-manager/internal/TestHooks.svelte.ts
@@ -1,16 +1,16 @@
-import type { DayGroup } from '$lib/managers/timeline-manager/day-group.svelte';
-import type { MonthGroup } from '$lib/managers/timeline-manager/month-group.svelte';
+import { TimelineDay } from '$lib/managers/timeline-manager/TimelineDay.svelte';
+import { TimelineMonth } from '$lib/managers/timeline-manager/TimelineMonth.svelte';
 
 let testHooks: TestHooks | undefined = undefined;
 
 export type TestHooks = {
-  onCreateMonthGroup(monthGroup: MonthGroup): unknown;
-  onCreateDayGroup(dayGroup: DayGroup): unknown;
+  onCreateMonth(month: TimelineMonth): unknown;
+  onCreateDay(day: TimelineDay): unknown;
 };
 
 export const setTestHooks = (hooks: TestHooks) => {
   testHooks = hooks;
 };
 
-export const onCreateMonthGroup = (monthGroup: MonthGroup) => testHooks?.onCreateMonthGroup(monthGroup);
-export const onCreateDayGroup = (dayGroup: DayGroup) => testHooks?.onCreateDayGroup(dayGroup);
+export const onCreateMonth = (month: TimelineMonth) => testHooks?.onCreateMonth(month);
+export const onCreateDay = (day: TimelineDay) => testHooks?.onCreateDay(day);
diff --git a/web/src/lib/managers/timeline-manager/internal/intersection-support.svelte.ts b/web/src/lib/managers/timeline-manager/internal/intersection-support.svelte.ts
index 3c6f2d8256..8026c69d49 100644
--- a/web/src/lib/managers/timeline-manager/internal/intersection-support.svelte.ts
+++ b/web/src/lib/managers/timeline-manager/internal/intersection-support.svelte.ts
@@ -1,16 +1,16 @@
+import { TimelineManager } from '$lib/managers/timeline-manager/TimelineManager.svelte';
+import { TimelineMonth } from '$lib/managers/timeline-manager/TimelineMonth.svelte';
 import { TUNABLES } from '$lib/utils/tunables';
-import type { MonthGroup } from '../month-group.svelte';
-import { TimelineManager } from '../timeline-manager.svelte';
 
 const {
   TIMELINE: { INTERSECTION_EXPAND_TOP, INTERSECTION_EXPAND_BOTTOM },
 } = TUNABLES;
 
-export function updateIntersectionMonthGroup(timelineManager: TimelineManager, month: MonthGroup) {
-  const actuallyIntersecting = calculateMonthGroupIntersecting(timelineManager, month, 0, 0);
+export function updateIntersectionMonth(timelineManager: TimelineManager, month: TimelineMonth) {
+  const actuallyIntersecting = calculateMonthIntersecting(timelineManager, month, 0, 0);
   let preIntersecting = false;
   if (!actuallyIntersecting) {
-    preIntersecting = calculateMonthGroupIntersecting(
+    preIntersecting = calculateMonthIntersecting(
       timelineManager,
       month,
       INTERSECTION_EXPAND_TOP,
@@ -40,18 +40,18 @@ export function isIntersecting(regionTop: number, regionBottom: number, windowTo
   );
 }
 
-export function calculateMonthGroupIntersecting(
+export function calculateMonthIntersecting(
   timelineManager: TimelineManager,
-  monthGroup: MonthGroup,
+  month: TimelineMonth,
   expandTop: number,
   expandBottom: number,
 ) {
-  const monthGroupTop = monthGroup.top;
-  const monthGroupBottom = monthGroupTop + monthGroup.height;
+  const monthTop = month.top;
+  const monthBottom = monthTop + month.height;
   const topWindow = timelineManager.visibleWindow.top - expandTop;
   const bottomWindow = timelineManager.visibleWindow.bottom + expandBottom;
 
-  return isIntersecting(monthGroupTop, monthGroupBottom, topWindow, bottomWindow);
+  return isIntersecting(monthTop, monthBottom, topWindow, bottomWindow);
 }
 
 /**
diff --git a/web/src/lib/managers/timeline-manager/internal/layout-support.svelte.ts b/web/src/lib/managers/timeline-manager/internal/layout-support.svelte.ts
index b5dd5d5f70..533294d8ea 100644
--- a/web/src/lib/managers/timeline-manager/internal/layout-support.svelte.ts
+++ b/web/src/lib/managers/timeline-manager/internal/layout-support.svelte.ts
@@ -1,8 +1,8 @@
-import type { MonthGroup } from '../month-group.svelte';
-import { TimelineManager } from '../timeline-manager.svelte';
-import type { UpdateGeometryOptions } from '../types';
+import { TimelineManager } from '$lib/managers/timeline-manager/TimelineManager.svelte';
+import { TimelineMonth } from '$lib/managers/timeline-manager/TimelineMonth.svelte';
+import type { UpdateGeometryOptions } from '$lib/managers/timeline-manager/types';
 
-export function updateGeometry(timelineManager: TimelineManager, month: MonthGroup, options: UpdateGeometryOptions) {
+export function updateGeometry(timelineManager: TimelineManager, month: TimelineMonth, options: UpdateGeometryOptions) {
   const { invalidateHeight, noDefer = false } = options;
   if (invalidateHeight) {
     month.isHeightActual = false;
@@ -17,49 +17,49 @@ export function updateGeometry(timelineManager: TimelineManager, month: MonthGro
     }
     return;
   }
-  layoutMonthGroup(timelineManager, month, noDefer);
+  layoutMonth(timelineManager, month, noDefer);
 }
 
-export function layoutMonthGroup(timelineManager: TimelineManager, month: MonthGroup, noDefer: boolean = false) {
+export function layoutMonth(timelineManager: TimelineManager, month: TimelineMonth, noDefer: boolean = false) {
   let cumulativeHeight = 0;
   let cumulativeWidth = 0;
   let currentRowHeight = 0;
 
-  let dayGroupRow = 0;
-  let dayGroupCol = 0;
+  let dayRow = 0;
+  let dayCol = 0;
 
   const options = timelineManager.justifiedLayoutOptions;
-  for (const dayGroup of month.dayGroups) {
-    dayGroup.layout(options, noDefer);
+  for (const day of month.days) {
+    day.layout(options, noDefer);
 
     // Calculate space needed for this item (including gap if not first in row)
-    const spaceNeeded = dayGroup.width + (dayGroupCol > 0 ? timelineManager.gap : 0);
+    const spaceNeeded = day.width + (dayCol > 0 ? timelineManager.gap : 0);
     const fitsInCurrentRow = cumulativeWidth + spaceNeeded <= timelineManager.viewportWidth;
 
     if (fitsInCurrentRow) {
-      dayGroup.row = dayGroupRow;
-      dayGroup.col = dayGroupCol++;
-      dayGroup.left = cumulativeWidth;
-      dayGroup.top = cumulativeHeight;
+      day.row = dayRow;
+      day.col = dayCol++;
+      day.left = cumulativeWidth;
+      day.top = cumulativeHeight;
 
-      cumulativeWidth += dayGroup.width + timelineManager.gap;
+      cumulativeWidth += day.width + timelineManager.gap;
     } else {
       // Move to next row
       cumulativeHeight += currentRowHeight;
       cumulativeWidth = 0;
-      dayGroupRow++;
-      dayGroupCol = 0;
+      dayRow++;
+      dayCol = 0;
 
       // Position at start of new row
-      dayGroup.row = dayGroupRow;
-      dayGroup.col = dayGroupCol;
-      dayGroup.left = 0;
-      dayGroup.top = cumulativeHeight;
+      day.row = dayRow;
+      day.col = dayCol;
+      day.left = 0;
+      day.top = cumulativeHeight;
 
-      dayGroupCol++;
-      cumulativeWidth += dayGroup.width + timelineManager.gap;
+      dayCol++;
+      cumulativeWidth += day.width + timelineManager.gap;
     }
-    currentRowHeight = dayGroup.height + timelineManager.headerHeight;
+    currentRowHeight = day.height + timelineManager.headerHeight;
   }
 
   // Add the height of the final row
diff --git a/web/src/lib/managers/timeline-manager/internal/load-support.svelte.ts b/web/src/lib/managers/timeline-manager/internal/load-support.svelte.ts
index 28e98f9deb..0c91a13d78 100644
--- a/web/src/lib/managers/timeline-manager/internal/load-support.svelte.ts
+++ b/web/src/lib/managers/timeline-manager/internal/load-support.svelte.ts
@@ -1,21 +1,21 @@
 import { authManager } from '$lib/managers/auth-manager.svelte';
+import { TimelineManager } from '$lib/managers/timeline-manager/TimelineManager.svelte';
+import { TimelineMonth } from '$lib/managers/timeline-manager/TimelineMonth.svelte';
+import type { TimelineManagerOptions } from '$lib/managers/timeline-manager/types';
 import { toISOYearMonthUTC } from '$lib/utils/timeline-util';
 import { getTimeBucket } from '@immich/sdk';
-import type { MonthGroup } from '../month-group.svelte';
-import { TimelineManager } from '../timeline-manager.svelte';
-import type { TimelineManagerOptions } from '../types';
 
 export async function loadFromTimeBuckets(
   timelineManager: TimelineManager,
-  monthGroup: MonthGroup,
+  month: TimelineMonth,
   options: TimelineManagerOptions,
   signal: AbortSignal,
 ): Promise<void> {
-  if (monthGroup.getFirstAsset()) {
+  if (month.getFirstAsset()) {
     return;
   }
 
-  const timeBucket = toISOYearMonthUTC(monthGroup.yearMonth);
+  const timeBucket = toISOYearMonthUTC(month.yearMonth);
   const bucketResponse = await getTimeBucket(
     {
       ...authManager.params,
@@ -43,10 +43,10 @@ export async function loadFromTimeBuckets(
     }
   }
 
-  const unprocessedAssets = monthGroup.addAssets(bucketResponse, true);
+  const unprocessedAssets = month.addAssets(bucketResponse, true);
   if (unprocessedAssets.length > 0) {
     console.error(
-      `Warning: getTimeBucket API returning assets not in requested month: ${monthGroup.yearMonth.month}, ${JSON.stringify(
+      `Warning: getTimeBucket API returning assets not in requested month: ${month.yearMonth.month}, ${JSON.stringify(
         unprocessedAssets.map((unprocessed) => ({
           id: unprocessed.id,
           localDateTime: unprocessed.localDateTime,
diff --git a/web/src/lib/managers/timeline-manager/internal/search-support.svelte.spec.ts b/web/src/lib/managers/timeline-manager/internal/search-support.svelte.spec.ts
index 2b8ca930eb..1a1881ad4d 100644
--- a/web/src/lib/managers/timeline-manager/internal/search-support.svelte.spec.ts
+++ b/web/src/lib/managers/timeline-manager/internal/search-support.svelte.spec.ts
@@ -1,11 +1,11 @@
+import { findClosestGroupForDate } from '$lib/managers/timeline-manager/internal/search-support.svelte';
+import { TimelineMonth } from '$lib/managers/timeline-manager/TimelineMonth.svelte';
 import { describe, expect, it } from 'vitest';
-import type { MonthGroup } from '../month-group.svelte';
-import { findClosestGroupForDate } from './search-support.svelte';
 
-function createMockMonthGroup(year: number, month: number): MonthGroup {
+function createMockMonth(year: number, month: number): TimelineMonth {
   return {
     yearMonth: { year, month },
-  } as MonthGroup;
+  } as TimelineMonth;
 }
 
 describe('findClosestGroupForDate', () => {
@@ -15,25 +15,25 @@ describe('findClosestGroupForDate', () => {
   });
 
   it('should return the only month when there is only one month', () => {
-    const months = [createMockMonthGroup(2024, 6)];
+    const months = [createMockMonth(2024, 6)];
     const result = findClosestGroupForDate(months, { year: 2025, month: 1 });
     expect(result?.yearMonth).toEqual({ year: 2024, month: 6 });
   });
 
   it('should return exact match when available', () => {
-    const months = [createMockMonthGroup(2024, 1), createMockMonthGroup(2024, 6), createMockMonthGroup(2024, 12)];
+    const months = [createMockMonth(2024, 1), createMockMonth(2024, 6), createMockMonth(2024, 12)];
     const result = findClosestGroupForDate(months, { year: 2024, month: 6 });
     expect(result?.yearMonth).toEqual({ year: 2024, month: 6 });
   });
 
   it('should find closest month when target is between two months', () => {
-    const months = [createMockMonthGroup(2024, 1), createMockMonthGroup(2024, 6), createMockMonthGroup(2024, 12)];
+    const months = [createMockMonth(2024, 1), createMockMonth(2024, 6), createMockMonth(2024, 12)];
     const result = findClosestGroupForDate(months, { year: 2024, month: 4 });
     expect(result?.yearMonth).toEqual({ year: 2024, month: 6 });
   });
 
   it('should handle year boundaries correctly (2023-12 vs 2024-01)', () => {
-    const months = [createMockMonthGroup(2023, 12), createMockMonthGroup(2024, 2)];
+    const months = [createMockMonth(2023, 12), createMockMonth(2024, 2)];
     const result = findClosestGroupForDate(months, { year: 2024, month: 1 });
     // 2024-01 is 1 month from 2023-12 and 1 month from 2024-02
     // Should return first encountered with min distance (2023-12)
@@ -41,33 +41,33 @@ describe('findClosestGroupForDate', () => {
   });
 
   it('should correctly calculate distance across years', () => {
-    const months = [createMockMonthGroup(2022, 6), createMockMonthGroup(2024, 6)];
+    const months = [createMockMonth(2022, 6), createMockMonth(2024, 6)];
     const result = findClosestGroupForDate(months, { year: 2023, month: 6 });
     // Both are exactly 12 months away, should return first encountered
     expect(result?.yearMonth).toEqual({ year: 2022, month: 6 });
   });
 
   it('should handle target before all months', () => {
-    const months = [createMockMonthGroup(2024, 6), createMockMonthGroup(2024, 12)];
+    const months = [createMockMonth(2024, 6), createMockMonth(2024, 12)];
     const result = findClosestGroupForDate(months, { year: 2024, month: 1 });
     expect(result?.yearMonth).toEqual({ year: 2024, month: 6 });
   });
 
   it('should handle target after all months', () => {
-    const months = [createMockMonthGroup(2024, 1), createMockMonthGroup(2024, 6)];
+    const months = [createMockMonth(2024, 1), createMockMonth(2024, 6)];
     const result = findClosestGroupForDate(months, { year: 2025, month: 1 });
     expect(result?.yearMonth).toEqual({ year: 2024, month: 6 });
   });
 
   it('should handle multiple years correctly', () => {
-    const months = [createMockMonthGroup(2020, 1), createMockMonthGroup(2022, 1), createMockMonthGroup(2024, 1)];
+    const months = [createMockMonth(2020, 1), createMockMonth(2022, 1), createMockMonth(2024, 1)];
     const result = findClosestGroupForDate(months, { year: 2023, month: 1 });
     // 2023-01 is 12 months from 2022-01 and 12 months from 2024-01
     expect(result?.yearMonth).toEqual({ year: 2022, month: 1 });
   });
 
   it('should prefer closer month when one is clearly closer', () => {
-    const months = [createMockMonthGroup(2024, 1), createMockMonthGroup(2024, 10)];
+    const months = [createMockMonth(2024, 1), createMockMonth(2024, 10)];
     const result = findClosestGroupForDate(months, { year: 2024, month: 11 });
     // 2024-11 is 1 month from 2024-10 and 10 months from 2024-01
     expect(result?.yearMonth).toEqual({ year: 2024, month: 10 });
diff --git a/web/src/lib/managers/timeline-manager/internal/search-support.svelte.ts b/web/src/lib/managers/timeline-manager/internal/search-support.svelte.ts
index f889456c20..375f7d9ff8 100644
--- a/web/src/lib/managers/timeline-manager/internal/search-support.svelte.ts
+++ b/web/src/lib/managers/timeline-manager/internal/search-support.svelte.ts
@@ -1,9 +1,9 @@
+import { TimelineManager } from '$lib/managers/timeline-manager/TimelineManager.svelte';
+import { TimelineMonth } from '$lib/managers/timeline-manager/TimelineMonth.svelte';
+import type { AssetDescriptor, Direction, TimelineAsset } from '$lib/managers/timeline-manager/types';
 import { plainDateTimeCompare, type TimelineYearMonth } from '$lib/utils/timeline-util';
 import { AssetOrder } from '@immich/sdk';
 import { DateTime } from 'luxon';
-import type { MonthGroup } from '../month-group.svelte';
-import { TimelineManager } from '../timeline-manager.svelte';
-import type { AssetDescriptor, Direction, TimelineAsset } from '../types';
 
 export async function getAssetWithOffset(
   timelineManager: TimelineManager,
@@ -11,40 +11,40 @@ export async function getAssetWithOffset(
   interval: 'asset' | 'day' | 'month' | 'year' = 'asset',
   direction: Direction,
 ): Promise<TimelineAsset | undefined> {
-  const { asset, monthGroup } = findMonthGroupForAsset(timelineManager, assetDescriptor.id) ?? {};
-  if (!monthGroup || !asset) {
+  const { asset, month } = findMonthForAsset(timelineManager, assetDescriptor.id) ?? {};
+  if (!month || !asset) {
     return;
   }
 
   switch (interval) {
     case 'asset': {
-      return getAssetByAssetOffset(timelineManager, asset, monthGroup, direction);
+      return getAssetByAssetOffset(timelineManager, asset, month, direction);
     }
     case 'day': {
-      return getAssetByDayOffset(timelineManager, asset, monthGroup, direction);
+      return getAssetByDayOffset(timelineManager, asset, month, direction);
     }
     case 'month': {
-      return getAssetByMonthOffset(timelineManager, monthGroup, direction);
+      return getAssetByMonthOffset(timelineManager, month, direction);
     }
     case 'year': {
-      return getAssetByYearOffset(timelineManager, monthGroup, direction);
+      return getAssetByYearOffset(timelineManager, month, direction);
     }
   }
 }
 
-export function findMonthGroupForAsset(timelineManager: TimelineManager, id: string) {
+export function findMonthForAsset(timelineManager: TimelineManager, id: string) {
   for (const month of timelineManager.months) {
     const asset = month.findAssetById({ id });
     if (asset) {
-      return { monthGroup: month, asset };
+      return { month, asset };
     }
   }
 }
 
-export function getMonthGroupByDate(
+export function getMonthByDate(
   timelineManager: TimelineManager,
   targetYearMonth: TimelineYearMonth,
-): MonthGroup | undefined {
+): TimelineMonth | undefined {
   return timelineManager.months.find(
     (month) => month.yearMonth.year === targetYearMonth.year && month.yearMonth.month === targetYearMonth.month,
   );
@@ -53,13 +53,13 @@ export function getMonthGroupByDate(
 async function getAssetByAssetOffset(
   timelineManager: TimelineManager,
   asset: TimelineAsset,
-  monthGroup: MonthGroup,
+  month: TimelineMonth,
   direction: Direction,
 ) {
-  const dayGroup = monthGroup.findDayGroupForAsset(asset);
+  const day = month.findDayForAsset(asset);
   for await (const targetAsset of timelineManager.assetsIterator({
-    startMonthGroup: monthGroup,
-    startDayGroup: dayGroup,
+    startMonth: month,
+    startDay: day,
     startAsset: asset,
     direction,
   })) {
@@ -72,13 +72,13 @@ async function getAssetByAssetOffset(
 async function getAssetByDayOffset(
   timelineManager: TimelineManager,
   asset: TimelineAsset,
-  monthGroup: MonthGroup,
+  month: TimelineMonth,
   direction: Direction,
 ) {
-  const dayGroup = monthGroup.findDayGroupForAsset(asset);
+  const day = month.findDayForAsset(asset);
   for await (const targetAsset of timelineManager.assetsIterator({
-    startMonthGroup: monthGroup,
-    startDayGroup: dayGroup,
+    startMonth: month,
+    startDay: day,
     startAsset: asset,
     direction,
   })) {
@@ -88,44 +88,44 @@ async function getAssetByDayOffset(
   }
 }
 
-async function getAssetByMonthOffset(timelineManager: TimelineManager, month: MonthGroup, direction: Direction) {
-  for (const targetMonth of timelineManager.monthGroupIterator({ startMonthGroup: month, direction })) {
+async function getAssetByMonthOffset(timelineManager: TimelineManager, month: TimelineMonth, direction: Direction) {
+  for (const targetMonth of timelineManager.monthIterator({ startMonth: month, direction })) {
     if (targetMonth.yearMonth.month !== month.yearMonth.month) {
-      const { value, done } = await timelineManager.assetsIterator({ startMonthGroup: targetMonth, direction }).next();
+      const { value, done } = await timelineManager.assetsIterator({ startMonth: targetMonth, direction }).next();
       return done ? undefined : value;
     }
   }
 }
 
-async function getAssetByYearOffset(timelineManager: TimelineManager, month: MonthGroup, direction: Direction) {
-  for (const targetMonth of timelineManager.monthGroupIterator({ startMonthGroup: month, direction })) {
+async function getAssetByYearOffset(timelineManager: TimelineManager, month: TimelineMonth, direction: Direction) {
+  for (const targetMonth of timelineManager.monthIterator({ startMonth: month, direction })) {
     if (targetMonth.yearMonth.year !== month.yearMonth.year) {
-      const { value, done } = await timelineManager.assetsIterator({ startMonthGroup: targetMonth, direction }).next();
+      const { value, done } = await timelineManager.assetsIterator({ startMonth: targetMonth, direction }).next();
       return done ? undefined : value;
     }
   }
 }
 
 export async function retrieveRange(timelineManager: TimelineManager, start: AssetDescriptor, end: AssetDescriptor) {
-  let { asset: startAsset, monthGroup: startMonthGroup } = findMonthGroupForAsset(timelineManager, start.id) ?? {};
-  if (!startMonthGroup || !startAsset) {
+  let { asset: startAsset, month: startMonth } = findMonthForAsset(timelineManager, start.id) ?? {};
+  if (!startMonth || !startAsset) {
     return [];
   }
-  let { asset: endAsset, monthGroup: endMonthGroup } = findMonthGroupForAsset(timelineManager, end.id) ?? {};
-  if (!endMonthGroup || !endAsset) {
+  let { asset: endAsset, month: endMonth } = findMonthForAsset(timelineManager, end.id) ?? {};
+  if (!endMonth || !endAsset) {
     return [];
   }
   const assetOrder: AssetOrder = timelineManager.getAssetOrder();
   if (plainDateTimeCompare(assetOrder === AssetOrder.Desc, startAsset.localDateTime, endAsset.localDateTime) < 0) {
     [startAsset, endAsset] = [endAsset, startAsset];
-    [startMonthGroup, endMonthGroup] = [endMonthGroup, startMonthGroup];
+    [startMonth, endMonth] = [endMonth, startMonth];
   }
 
   const range: TimelineAsset[] = [];
-  const startDayGroup = startMonthGroup.findDayGroupForAsset(startAsset);
+  const startDay = startMonth.findDayForAsset(startAsset);
   for await (const targetAsset of timelineManager.assetsIterator({
-    startMonthGroup,
-    startDayGroup,
+    startMonth,
+    startDay,
     startAsset,
   })) {
     range.push(targetAsset);
@@ -136,7 +136,7 @@ export async function retrieveRange(timelineManager: TimelineManager, start: Ass
   return range;
 }
 
-export function findMonthGroupForDate(timelineManager: TimelineManager, targetYearMonth: TimelineYearMonth) {
+export function findMonthForDate(timelineManager: TimelineManager, targetYearMonth: TimelineYearMonth) {
   for (const month of timelineManager.months) {
     const { year, month: monthNum } = month.yearMonth;
     if (monthNum === targetYearMonth.month && year === targetYearMonth.year) {
@@ -145,10 +145,10 @@ export function findMonthGroupForDate(timelineManager: TimelineManager, targetYe
   }
 }
 
-export function findClosestGroupForDate(months: MonthGroup[], targetYearMonth: TimelineYearMonth) {
+export function findClosestGroupForDate(months: TimelineMonth[], targetYearMonth: TimelineYearMonth) {
   const targetDate = DateTime.fromObject({ year: targetYearMonth.year, month: targetYearMonth.month });
 
-  let closestMonth: MonthGroup | undefined;
+  let closestMonth: TimelineMonth | undefined;
   let minDifference = Number.MAX_SAFE_INTEGER;
 
   for (const month of months) {
diff --git a/web/src/lib/managers/timeline-manager/internal/websocket-support.svelte.ts b/web/src/lib/managers/timeline-manager/internal/websocket-support.svelte.ts
index 9488811fe8..321996205c 100644
--- a/web/src/lib/managers/timeline-manager/internal/websocket-support.svelte.ts
+++ b/web/src/lib/managers/timeline-manager/internal/websocket-support.svelte.ts
@@ -1,4 +1,4 @@
-import { TimelineManager } from '$lib/managers/timeline-manager/timeline-manager.svelte';
+import { TimelineManager } from '$lib/managers/timeline-manager/TimelineManager.svelte';
 import type { PendingChange, TimelineAsset } from '$lib/managers/timeline-manager/types';
 import { websocketEvents } from '$lib/stores/websocket';
 import { toTimelineAsset } from '$lib/utils/timeline-util';
diff --git a/web/src/lib/managers/timeline-manager/utils.svelte.ts b/web/src/lib/managers/timeline-manager/utils.svelte.ts
index 2aba6470ee..004695e9c1 100644
--- a/web/src/lib/managers/timeline-manager/utils.svelte.ts
+++ b/web/src/lib/managers/timeline-manager/utils.svelte.ts
@@ -1,4 +1,4 @@
-import type { TimelineAsset } from './types';
+import type { TimelineAsset } from '$lib/managers/timeline-manager/types';
 
 export const assetSnapshot = (asset: TimelineAsset): TimelineAsset => $state.snapshot(asset);
 export const assetsSnapshot = (assets: TimelineAsset[]) => assets.map((asset) => $state.snapshot(asset));
diff --git a/web/src/lib/managers/timeline-manager/viewer-asset.svelte.ts b/web/src/lib/managers/timeline-manager/viewer-asset.svelte.ts
index 161cc049f1..6ae5f4a2bc 100644
--- a/web/src/lib/managers/timeline-manager/viewer-asset.svelte.ts
+++ b/web/src/lib/managers/timeline-manager/viewer-asset.svelte.ts
@@ -1,19 +1,18 @@
+import { calculateViewerAssetIntersecting } from '$lib/managers/timeline-manager/internal/intersection-support.svelte';
+import { TimelineDay } from '$lib/managers/timeline-manager/TimelineDay.svelte';
+import type { TimelineAsset } from '$lib/managers/timeline-manager/types';
 import type { CommonPosition } from '$lib/utils/layout-utils';
 
-import type { DayGroup } from './day-group.svelte';
-import { calculateViewerAssetIntersecting } from './internal/intersection-support.svelte';
-import type { TimelineAsset } from './types';
-
 export class ViewerAsset {
-  readonly #group: DayGroup;
+  readonly #day: TimelineDay;
 
   intersecting = $derived.by(() => {
     if (!this.position) {
       return false;
     }
 
-    const store = this.#group.monthGroup.timelineManager;
-    const positionTop = this.#group.absoluteDayGroupTop + this.position.top;
+    const store = this.#day.month.timelineManager;
+    const positionTop = this.#day.absoluteTop + this.position.top;
 
     return calculateViewerAssetIntersecting(store, positionTop, this.position.height);
   });
@@ -22,8 +21,8 @@ export class ViewerAsset {
   asset: TimelineAsset = <TimelineAsset>$state();
   id: string = $derived(this.asset.id);
 
-  constructor(group: DayGroup, asset: TimelineAsset) {
-    this.#group = group;
+  constructor(day: TimelineDay, asset: TimelineAsset) {
+    this.#day = day;
     this.asset = asset;
   }
 }
diff --git a/web/src/lib/modals/NavigateToDateModal.svelte b/web/src/lib/modals/NavigateToDateModal.svelte
index 365cbdb21c..b1cec1ff92 100644
--- a/web/src/lib/modals/NavigateToDateModal.svelte
+++ b/web/src/lib/modals/NavigateToDateModal.svelte
@@ -1,6 +1,6 @@
 <script lang="ts">
   import DateInput from '$lib/elements/DateInput.svelte';
-  import { TimelineManager } from '$lib/managers/timeline-manager/timeline-manager.svelte';
+  import { TimelineManager } from '$lib/managers/timeline-manager/TimelineManager.svelte';
   import type { TimelineAsset } from '$lib/managers/timeline-manager/types';
   import { getPreferredTimeZone, getTimezones, toDatetime, type ZoneOption } from '$lib/modals/timezone-utils';
   import { Button, HStack, Modal, ModalBody, ModalFooter, VStack } from '@immich/ui';
diff --git a/web/src/lib/utils/actions.ts b/web/src/lib/utils/actions.ts
index 150bfc2bd7..c6e7bf7516 100644
--- a/web/src/lib/utils/actions.ts
+++ b/web/src/lib/utils/actions.ts
@@ -1,5 +1,5 @@
 import ToastAction from '$lib/components/ToastAction.svelte';
-import { TimelineManager } from '$lib/managers/timeline-manager/timeline-manager.svelte';
+import { TimelineManager } from '$lib/managers/timeline-manager/TimelineManager.svelte';
 import type { TimelineAsset } from '$lib/managers/timeline-manager/types';
 import type { StackResponse } from '$lib/utils/asset-utils';
 import { AssetVisibility, deleteAssets as deleteBulk, restoreAssets } from '@immich/sdk';
diff --git a/web/src/lib/utils/asset-utils.ts b/web/src/lib/utils/asset-utils.ts
index c8f120b38f..ea4646ba2d 100644
--- a/web/src/lib/utils/asset-utils.ts
+++ b/web/src/lib/utils/asset-utils.ts
@@ -3,7 +3,7 @@ import ToastAction from '$lib/components/ToastAction.svelte';
 import { AppRoute } from '$lib/constants';
 import { authManager } from '$lib/managers/auth-manager.svelte';
 import { downloadManager } from '$lib/managers/download-manager.svelte';
-import { TimelineManager } from '$lib/managers/timeline-manager/timeline-manager.svelte';
+import { TimelineManager } from '$lib/managers/timeline-manager/TimelineManager.svelte';
 import type { TimelineAsset } from '$lib/managers/timeline-manager/types';
 import { assetsSnapshot } from '$lib/managers/timeline-manager/utils.svelte';
 import type { AssetInteraction } from '$lib/stores/asset-interaction.svelte';
@@ -490,17 +490,17 @@ export const selectAllAssets = async (timelineManager: TimelineManager, assetInt
   isSelectingAllAssets.set(true);
 
   try {
-    for (const monthGroup of timelineManager.months) {
-      await timelineManager.loadMonthGroup(monthGroup.yearMonth);
+    for (const month of timelineManager.months) {
+      await timelineManager.loadMonth(month.yearMonth);
 
       if (!get(isSelectingAllAssets)) {
         assetInteraction.clearMultiselect();
         break; // Cancelled
       }
-      assetInteraction.selectAssets(assetsSnapshot([...monthGroup.assetsIterator()]));
+      assetInteraction.selectAssets(assetsSnapshot([...month.assetsIterator()]));
 
-      for (const dateGroup of monthGroup.dayGroups) {
-        assetInteraction.addGroupToMultiselectGroup(dateGroup.groupTitle);
+      for (const dateGroup of month.days) {
+        assetInteraction.addGroupToMultiselectGroup(dateGroup.dayTitle);
       }
     }
   } catch (error) {
diff --git a/web/src/lib/utils/timeline-util.spec.ts b/web/src/lib/utils/timeline-util.spec.ts
index bc05b78ad4..709361eaaf 100644
--- a/web/src/lib/utils/timeline-util.spec.ts
+++ b/web/src/lib/utils/timeline-util.spec.ts
@@ -1,9 +1,9 @@
 import { locale } from '$lib/stores/preferences.store';
 import { parseUtcDate } from '$lib/utils/date-time';
-import { formatGroupTitle, toISOYearMonthUTC } from '$lib/utils/timeline-util';
+import { formatDayTitle, toISOYearMonthUTC } from '$lib/utils/timeline-util';
 import { DateTime } from 'luxon';
 
-describe('formatGroupTitle', () => {
+describe('formatDayTitle', () => {
   beforeAll(() => {
     vi.useFakeTimers();
     process.env.TZ = 'UTC';
@@ -18,63 +18,63 @@ describe('formatGroupTitle', () => {
   it('formats today', () => {
     const date = parseUtcDate('2024-07-27T01:00:00Z');
     locale.set('en');
-    expect(formatGroupTitle(date)).toBe('today');
+    expect(formatDayTitle(date)).toBe('today');
     locale.set('es');
-    expect(formatGroupTitle(date)).toBe('hoy');
+    expect(formatDayTitle(date)).toBe('hoy');
   });
 
   it('formats yesterday', () => {
     const date = parseUtcDate('2024-07-26T23:59:59Z');
     locale.set('en');
-    expect(formatGroupTitle(date)).toBe('yesterday');
+    expect(formatDayTitle(date)).toBe('yesterday');
     locale.set('fr');
-    expect(formatGroupTitle(date)).toBe('hier');
+    expect(formatDayTitle(date)).toBe('hier');
   });
 
   it('formats last week', () => {
     const date = parseUtcDate('2024-07-21T00:00:00Z');
     locale.set('en');
-    expect(formatGroupTitle(date)).toBe('Sunday');
+    expect(formatDayTitle(date)).toBe('Sunday');
     locale.set('ar-SA');
-    expect(formatGroupTitle(date)).toBe('الأحد');
+    expect(formatDayTitle(date)).toBe('الأحد');
   });
 
   it('formats date 7 days ago', () => {
     const date = parseUtcDate('2024-07-20T00:00:00Z');
     locale.set('en');
-    expect(formatGroupTitle(date)).toBe('Sat, Jul 20');
+    expect(formatDayTitle(date)).toBe('Sat, Jul 20');
     locale.set('de');
-    expect(formatGroupTitle(date)).toBe('Sa., 20. Juli');
+    expect(formatDayTitle(date)).toBe('Sa., 20. Juli');
   });
 
   it('formats date this year', () => {
     const date = parseUtcDate('2020-01-01T00:00:00Z');
     locale.set('en');
-    expect(formatGroupTitle(date)).toBe('Wed, Jan 1, 2020');
+    expect(formatDayTitle(date)).toBe('Wed, Jan 1, 2020');
     locale.set('ja');
-    expect(formatGroupTitle(date)).toBe('2020年1月1日(水)');
+    expect(formatDayTitle(date)).toBe('2020年1月1日(水)');
   });
 
   it('formats future date', () => {
     const tomorrow = parseUtcDate('2024-07-28T00:00:00Z');
     locale.set('en');
-    expect(formatGroupTitle(tomorrow)).toBe('Sun, Jul 28');
+    expect(formatDayTitle(tomorrow)).toBe('Sun, Jul 28');
 
     const nextMonth = parseUtcDate('2024-08-28T00:00:00Z');
     locale.set('en');
-    expect(formatGroupTitle(nextMonth)).toBe('Wed, Aug 28');
+    expect(formatDayTitle(nextMonth)).toBe('Wed, Aug 28');
 
     const nextYear = parseUtcDate('2025-01-10T12:00:00Z');
     locale.set('en');
-    expect(formatGroupTitle(nextYear)).toBe('Fri, Jan 10, 2025');
+    expect(formatDayTitle(nextYear)).toBe('Fri, Jan 10, 2025');
   });
 
   it('returns "Invalid DateTime" when date is invalid', () => {
     const date = DateTime.invalid('test');
     locale.set('en');
-    expect(formatGroupTitle(date)).toBe('Invalid DateTime');
+    expect(formatDayTitle(date)).toBe('Invalid DateTime');
     locale.set('es');
-    expect(formatGroupTitle(date)).toBe('Invalid DateTime');
+    expect(formatDayTitle(date)).toBe('Invalid DateTime');
   });
 });
 
diff --git a/web/src/lib/utils/timeline-util.ts b/web/src/lib/utils/timeline-util.ts
index 6b50cf71eb..9d8e9d274e 100644
--- a/web/src/lib/utils/timeline-util.ts
+++ b/web/src/lib/utils/timeline-util.ts
@@ -99,7 +99,7 @@ export const toISOYearMonthUTC = ({ year, month }: TimelineYearMonth): string =>
   return `${yearFull}-${monthFull}-01T00:00:00.000Z`;
 };
 
-export function formatMonthGroupTitle(_date: DateTime): string {
+export function formatMonthTitle(_date: DateTime): string {
   if (!_date.isValid) {
     return _date.toString();
   }
@@ -113,7 +113,7 @@ export function formatMonthGroupTitle(_date: DateTime): string {
   );
 }
 
-export function formatGroupTitle(_date: DateTime): string {
+export function formatDayTitle(_date: DateTime): string {
   if (!_date.isValid) {
     return _date.toString();
   }
diff --git a/web/src/routes/(user)/albums/[albumId=id]/[[photos=photos]]/[[assetId=id]]/+page.svelte b/web/src/routes/(user)/albums/[albumId=id]/[[photos=photos]]/[[assetId=id]]/+page.svelte
index 2391c66d19..6d17547d32 100644
--- a/web/src/routes/(user)/albums/[albumId=id]/[[photos=photos]]/[[assetId=id]]/+page.svelte
+++ b/web/src/routes/(user)/albums/[albumId=id]/[[photos=photos]]/[[assetId=id]]/+page.svelte
@@ -29,7 +29,7 @@
   import Timeline from '$lib/components/timeline/Timeline.svelte';
   import { AlbumPageViewMode, AppRoute } from '$lib/constants';
   import { activityManager } from '$lib/managers/activity-manager.svelte';
-  import { TimelineManager } from '$lib/managers/timeline-manager/timeline-manager.svelte';
+  import { TimelineManager } from '$lib/managers/timeline-manager/TimelineManager.svelte';
   import type { TimelineAsset } from '$lib/managers/timeline-manager/types';
   import AlbumOptionsModal from '$lib/modals/AlbumOptionsModal.svelte';
   import AlbumShareModal from '$lib/modals/AlbumShareModal.svelte';
@@ -141,7 +141,7 @@
     const asset =
       $slideshowNavigation === SlideshowNavigation.Shuffle
         ? await timelineManager.getRandomAsset()
-        : timelineManager.months[0]?.dayGroups[0]?.viewerAssets[0]?.asset;
+        : timelineManager.months[0]?.days[0]?.viewerAssets[0]?.asset;
     if (asset) {
       handlePromiseError(setAssetId(asset.id).then(() => ($slideshowState = SlideshowState.PlaySlideshow)));
     }
diff --git a/web/src/routes/(user)/archive/[[photos=photos]]/[[assetId=id]]/+page.svelte b/web/src/routes/(user)/archive/[[photos=photos]]/[[assetId=id]]/+page.svelte
index 165ef59344..6703145a41 100644
--- a/web/src/routes/(user)/archive/[[photos=photos]]/[[assetId=id]]/+page.svelte
+++ b/web/src/routes/(user)/archive/[[photos=photos]]/[[assetId=id]]/+page.svelte
@@ -14,7 +14,7 @@
   import { AssetAction } from '$lib/constants';
 
   import SetVisibilityAction from '$lib/components/timeline/actions/SetVisibilityAction.svelte';
-  import { TimelineManager } from '$lib/managers/timeline-manager/timeline-manager.svelte';
+  import { TimelineManager } from '$lib/managers/timeline-manager/TimelineManager.svelte';
   import { AssetInteraction } from '$lib/stores/asset-interaction.svelte';
   import { AssetVisibility } from '@immich/sdk';
   import { mdiDotsVertical, mdiPlus } from '@mdi/js';
diff --git a/web/src/routes/(user)/favorites/[[photos=photos]]/[[assetId=id]]/+page.svelte b/web/src/routes/(user)/favorites/[[photos=photos]]/[[assetId=id]]/+page.svelte
index c962ea0685..b6bce7a82a 100644
--- a/web/src/routes/(user)/favorites/[[photos=photos]]/[[assetId=id]]/+page.svelte
+++ b/web/src/routes/(user)/favorites/[[photos=photos]]/[[assetId=id]]/+page.svelte
@@ -17,7 +17,7 @@
   import AssetSelectControlBar from '$lib/components/timeline/AssetSelectControlBar.svelte';
   import Timeline from '$lib/components/timeline/Timeline.svelte';
   import { AssetAction } from '$lib/constants';
-  import { TimelineManager } from '$lib/managers/timeline-manager/timeline-manager.svelte';
+  import { TimelineManager } from '$lib/managers/timeline-manager/TimelineManager.svelte';
   import { AssetInteraction } from '$lib/stores/asset-interaction.svelte';
   import { preferences } from '$lib/stores/user.store';
   import { mdiDotsVertical, mdiPlus } from '@mdi/js';
diff --git a/web/src/routes/(user)/locked/[[photos=photos]]/[[assetId=id]]/+page.svelte b/web/src/routes/(user)/locked/[[photos=photos]]/[[assetId=id]]/+page.svelte
index 510b609784..1bc03f4ee4 100644
--- a/web/src/routes/(user)/locked/[[photos=photos]]/[[assetId=id]]/+page.svelte
+++ b/web/src/routes/(user)/locked/[[photos=photos]]/[[assetId=id]]/+page.svelte
@@ -12,7 +12,7 @@
   import AssetSelectControlBar from '$lib/components/timeline/AssetSelectControlBar.svelte';
   import Timeline from '$lib/components/timeline/Timeline.svelte';
   import { AppRoute, AssetAction } from '$lib/constants';
-  import { TimelineManager } from '$lib/managers/timeline-manager/timeline-manager.svelte';
+  import { TimelineManager } from '$lib/managers/timeline-manager/TimelineManager.svelte';
   import { AssetInteraction } from '$lib/stores/asset-interaction.svelte';
   import { AssetVisibility, lockAuthSession } from '@immich/sdk';
   import { Button } from '@immich/ui';
diff --git a/web/src/routes/(user)/people/[personId]/[[photos=photos]]/[[assetId=id]]/+page.svelte b/web/src/routes/(user)/people/[personId]/[[photos=photos]]/[[assetId=id]]/+page.svelte
index 5abcc6f5a3..d22db458b9 100644
--- a/web/src/routes/(user)/people/[personId]/[[photos=photos]]/[[assetId=id]]/+page.svelte
+++ b/web/src/routes/(user)/people/[personId]/[[photos=photos]]/[[assetId=id]]/+page.svelte
@@ -26,7 +26,7 @@
   import AssetSelectControlBar from '$lib/components/timeline/AssetSelectControlBar.svelte';
   import Timeline from '$lib/components/timeline/Timeline.svelte';
   import { AppRoute, PersonPageViewMode, QueryParameter, SessionStorageKey } from '$lib/constants';
-  import { TimelineManager } from '$lib/managers/timeline-manager/timeline-manager.svelte';
+  import { TimelineManager } from '$lib/managers/timeline-manager/TimelineManager.svelte';
   import type { TimelineAsset } from '$lib/managers/timeline-manager/types';
   import PersonEditBirthDateModal from '$lib/modals/PersonEditBirthDateModal.svelte';
   import PersonMergeSuggestionModal from '$lib/modals/PersonMergeSuggestionModal.svelte';
diff --git a/web/src/routes/(user)/photos/[[assetId=id]]/+page.svelte b/web/src/routes/(user)/photos/[[assetId=id]]/+page.svelte
index 12e59c0261..a362f4af7f 100644
--- a/web/src/routes/(user)/photos/[[assetId=id]]/+page.svelte
+++ b/web/src/routes/(user)/photos/[[assetId=id]]/+page.svelte
@@ -22,7 +22,7 @@
   import AssetSelectControlBar from '$lib/components/timeline/AssetSelectControlBar.svelte';
   import Timeline from '$lib/components/timeline/Timeline.svelte';
   import { AssetAction } from '$lib/constants';
-  import { TimelineManager } from '$lib/managers/timeline-manager/timeline-manager.svelte';
+  import { TimelineManager } from '$lib/managers/timeline-manager/TimelineManager.svelte';
   import { AssetInteraction } from '$lib/stores/asset-interaction.svelte';
   import { assetViewingStore } from '$lib/stores/asset-viewing.store';
   import { isFaceEditMode } from '$lib/stores/face-edit.svelte';
diff --git a/web/src/routes/(user)/tags/[[photos=photos]]/[[assetId=id]]/+page.svelte b/web/src/routes/(user)/tags/[[photos=photos]]/[[assetId=id]]/+page.svelte
index 442d3cef6c..60cda27bbb 100644
--- a/web/src/routes/(user)/tags/[[photos=photos]]/[[assetId=id]]/+page.svelte
+++ b/web/src/routes/(user)/tags/[[photos=photos]]/[[assetId=id]]/+page.svelte
@@ -8,7 +8,7 @@
   import Timeline from '$lib/components/timeline/Timeline.svelte';
   import { AppRoute, AssetAction, QueryParameter } from '$lib/constants';
   import SkipLink from '$lib/elements/SkipLink.svelte';
-  import { TimelineManager } from '$lib/managers/timeline-manager/timeline-manager.svelte';
+  import { TimelineManager } from '$lib/managers/timeline-manager/TimelineManager.svelte';
   import TagCreateModal from '$lib/modals/TagCreateModal.svelte';
   import TagEditModal from '$lib/modals/TagEditModal.svelte';
   import { AssetInteraction } from '$lib/stores/asset-interaction.svelte';
diff --git a/web/src/routes/(user)/trash/[[photos=photos]]/[[assetId=id]]/+page.svelte b/web/src/routes/(user)/trash/[[photos=photos]]/[[assetId=id]]/+page.svelte
index f12d8c80d3..c4fce1aff6 100644
--- a/web/src/routes/(user)/trash/[[photos=photos]]/[[assetId=id]]/+page.svelte
+++ b/web/src/routes/(user)/trash/[[photos=photos]]/[[assetId=id]]/+page.svelte
@@ -9,7 +9,7 @@
   import AssetSelectControlBar from '$lib/components/timeline/AssetSelectControlBar.svelte';
   import Timeline from '$lib/components/timeline/Timeline.svelte';
   import { AppRoute } from '$lib/constants';
-  import { TimelineManager } from '$lib/managers/timeline-manager/timeline-manager.svelte';
+  import { TimelineManager } from '$lib/managers/timeline-manager/TimelineManager.svelte';
   import { AssetInteraction } from '$lib/stores/asset-interaction.svelte';
   import { featureFlags, serverConfig } from '$lib/stores/server-config.store';
   import { handlePromiseError } from '$lib/utils';
diff --git a/web/src/routes/(user)/utilities/geolocation/+page.svelte b/web/src/routes/(user)/utilities/geolocation/+page.svelte
index 3dcb9b68cd..6c45b58fef 100644
--- a/web/src/routes/(user)/utilities/geolocation/+page.svelte
+++ b/web/src/routes/(user)/utilities/geolocation/+page.svelte
@@ -5,8 +5,8 @@
   import Timeline from '$lib/components/timeline/Timeline.svelte';
   import { AssetAction } from '$lib/constants';
   import { authManager } from '$lib/managers/auth-manager.svelte';
-  import type { DayGroup } from '$lib/managers/timeline-manager/day-group.svelte';
-  import { TimelineManager } from '$lib/managers/timeline-manager/timeline-manager.svelte';
+  import { TimelineDay } from '$lib/managers/timeline-manager/TimelineDay.svelte';
+  import { TimelineManager } from '$lib/managers/timeline-manager/TimelineManager.svelte';
   import type { TimelineAsset } from '$lib/managers/timeline-manager/types';
   import GeolocationUpdateConfirmModal from '$lib/modals/GeolocationUpdateConfirmModal.svelte';
   import { AssetInteraction } from '$lib/stores/asset-interaction.svelte';
@@ -113,11 +113,11 @@
   const handleThumbnailClick = (
     asset: TimelineAsset,
     timelineManager: TimelineManager,
-    dayGroup: DayGroup,
+    day: TimelineDay,
     onClick: (
       timelineManager: TimelineManager,
       assets: TimelineAsset[],
-      groupTitle: string,
+      dayTitle: string,
       asset: TimelineAsset,
     ) => void,
   ) => {
@@ -129,7 +129,7 @@
       location = { latitude: asset.latitude!, longitude: asset.longitude! };
       void setQueryValue('at', asset.id);
     } else {
-      onClick(timelineManager, dayGroup.getAssets(), dayGroup.groupTitle, asset);
+      onClick(timelineManager, day.getAssets(), day.dayTitle, asset);
     }
   };
 </script>