fix(timer): keep day offset on count-to-end scheduled end

getExpectedEnd compared the offset-laden expectedStart against a raw
`timeStart + duration + delay` planned end. That planned end omits the
`(dayOffset - currentDay) * dayInMs` day shift that expectedStart already
carries, so for a count-to-end event on a later day the Math.max guard
returned the day-shifted start instead of the day-shifted end (wrong by
one duration).

Compute the scheduled end in the same day-normalised space before the
guard. The guard itself (finish on schedule unless the start is
compromised) is unchanged.

Add unit tests for the multi-day case, the compromised-start guard, and
relative mode.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01ACGuFWt5aN7Fv3AkYXgxLm

.nvmrc

@@ -1 +1 @@
-v22.22.2
+v22.22.3

apps/client/package.json

@@ -4,7 +4,7 @@
   "private": true,
   "type": "module",
   "dependencies": {
-    "@base-ui/react": "1.3.0",
+    "@base-ui/react": "1.6.0",
     "@codemirror/commands": "^6.0.0",
     "@codemirror/lang-css": "^6.0.0",
     "@codemirror/state": "^6.0.0",
@@ -12,27 +12,27 @@
     "@dnd-kit/core": "^6.3.1",
     "@dnd-kit/sortable": "^10.0.0",
     "@dnd-kit/utilities": "^3.2.2",
-    "@fontsource/open-sans": "^5.2.6",
+    "@fontsource/open-sans": "^5.2.7",
     "@mantine/hooks": "^8.3.7",
-    "@sentry/react": "^10.2.0",
+    "@sentry/react": "^10.59.0",
     "@table-nav/react": "^0.0.7",
-    "@tanstack/react-query": "^5.85.9",
-    "@tanstack/react-query-devtools": "^5.85.9",
+    "@tanstack/react-query": "^5.101.0",
+    "@tanstack/react-query-devtools": "^5.101.0",
     "@tanstack/react-table": "^8.21.3",
-    "@uiw/codemirror-theme-vscode": "^4.25.9",
+    "@uiw/codemirror-theme-vscode": "^4.25.10",
     "autosize": "^6.0.1",
-    "axios": "^1.12.2",
+    "axios": "^1.18.0",
     "csv-stringify": "^6.6.0",
     "qrcode": "^1.5.4",
-    "react": "^19.2.3",
-    "react-colorful": "^5.6.1",
-    "react-dom": "^19.2.3",
+    "react": "^19.2.7",
+    "react-colorful": "^5.7.0",
+    "react-dom": "^19.2.7",
     "react-fast-compare": "^3.2.2",
-    "react-hook-form": "^7.72.0",
-    "react-icons": "5.5.0",
-    "react-router": "^7.11.0",
-    "react-virtuoso": "^4.17.0",
-    "zustand": "^5.0.9"
+    "react-hook-form": "^7.80.0",
+    "react-icons": "5.6.0",
+    "react-router": "^8.0.1",
+    "react-virtuoso": "^4.18.7",
+    "zustand": "^5.0.14"
   },
   "scripts": {
     "addversion": "node -p \"'export const ONTIME_VERSION = ' + JSON.stringify(require('../../package.json').version) + ';'\" > src/ONTIME_VERSION.js",

apps/client/src/common/components/state/EmptyTableBody.module.scss

@@ -8,9 +8,12 @@
     padding-top: 10vh;
   }
 
-  .empty {
-    width: 100%;
-    opacity: 0.8;
+  .inline {
+    display: flex;
+    align-items: center;
+    justify-content: center;
+    gap: 1rem;
+    margin-top: 1em;
   }
 
   .text {

apps/client/src/common/components/state/EmptyTableBody.tsx

@@ -1,18 +1,33 @@
-import EmptyImage from '../../../assets/images/empty.svg?react';
+import { SupportedEntry } from 'ontime-types';
+import { IoAdd } from 'react-icons/io5';
+
+import { useTranslation } from '../../../translation/TranslationProvider';
+import Button from '../buttons/Button';
+import Empty from './Empty';
 
 import style from './EmptyTableBody.module.scss';
 
 interface EmptyTableBodyProps {
-  text: string;
+  handleAddNew?: (type: SupportedEntry) => void;
 }
 
-export default function EmptyTableBody({ text }: EmptyTableBodyProps) {
+export default function EmptyTableBody({ handleAddNew }: EmptyTableBodyProps) {
+  const { getLocalizedString } = useTranslation();
+  const text = getLocalizedString('common.no_data');
   return (
     <tbody className={style.emptyContainer}>
       <tr>
         <td colSpan={99} className={style.emptyCell}>
-          <EmptyImage className={style.empty} />
-          {text && <span className={style.text}>{text}</span>}
+          <Empty injectedStyles={{ marginTop: '5vh' }} />
+          <span className={style.text}>{text}</span>
+          {handleAddNew && (
+            <div className={style.inline}>
+              <Button onClick={() => handleAddNew(SupportedEntry.Event)} variant='primary' size='large'>
+                <IoAdd />
+                Create Event
+              </Button>
+            </div>
+          )}
         </td>
       </tr>
     </tbody>

apps/client/src/common/utils/__tests__/urlPresets.test.ts

@@ -40,6 +40,15 @@ describe('getRouteFromPreset()', () => {
       options: {},
     },
   ];
+  const disabledPresets: URLPreset[] = [
+    {
+      enabled: false,
+      alias: 'demopage',
+      target: OntimeView.Timer,
+      search: 'user=guest',
+      options: {},
+    },
+  ];
 
   it('checks if the current location matches an enabled preset', () => {
     // we make the current location be the alias
@@ -47,6 +56,16 @@ describe('getRouteFromPreset()', () => {
     expect(getRouteFromPreset(location, presets)).toStrictEqual('timer?user=guest&alias=demopage');
   });
 
+  it('checks if the current location matches an enabled preset target', () => {
+    const location = resolvePath('/timer');
+    expect(getRouteFromPreset(location, presets)).toStrictEqual('timer?user=guest&alias=demopage');
+  });
+
+  it('does not redirect disabled presets', () => {
+    const location = resolvePath('/demopage');
+    expect(getRouteFromPreset(location, disabledPresets)).toBeNull();
+  });
+
   it('returns null when already on a preset path', () => {
     const location = resolvePath('/preset/demopage');
     expect(getRouteFromPreset(location, presets)).toBeNull();
@@ -86,6 +105,11 @@ describe('getRouteFromPreset()', () => {
       const location = resolvePath('/demopage?n=1&token=123');
       expect(getRouteFromPreset(location, presets)).toBe('timer?user=guest&alias=demopage&n=1&token=123');
     });
+
+    it('redirects stale unwrapped params back to the saved preset params while preserving feature params', () => {
+      const location = resolvePath('/timer?user=admin&alias=demopage&n=1&token=123');
+      expect(getRouteFromPreset(location, presets)).toBe('timer?user=guest&alias=demopage&n=1&token=123');
+    });
   });
 
   describe('cuesheet presets', () => {

apps/client/src/common/utils/time.ts

@@ -4,6 +4,7 @@ import {
   MILLIS_PER_MINUTE,
   MILLIS_PER_SECOND,
   formatFromMillis,
+  getExpectedEnd,
   getExpectedStart,
 } from 'ontime-utils';
 
@@ -172,13 +173,15 @@ export function getExpectedTimesFromExtendedEvent(
 ) {
   if (event === null) return { expectedStart: 0, timeToStart: 0, expectedEnd: 0, plannedEnd: 0 };
 
+  const expectedStartState = {
+    totalGap: event.totalGap,
+    isLinkedToLoaded: event.isLinkedToLoaded,
+    ...state,
+  };
+
   const expectedStart = getExpectedStart(
     { timeStart: event.timeStart, delay: event.delay, dayOffset: event.dayOffset },
-    {
-      totalGap: event.totalGap,
-      isLinkedToLoaded: event.isLinkedToLoaded,
-      ...state,
-    },
+    expectedStartState,
   );
 
   const plannedEnd = event.timeStart + event.duration + event.delay;
@@ -186,9 +189,7 @@ export function getExpectedTimesFromExtendedEvent(
   return {
     expectedStart,
     timeToStart: expectedStart - state.clock,
-    expectedEnd: event.countToEnd
-      ? Math.max(expectedStart + event.duration, plannedEnd)
-      : expectedStart + event.duration,
+    expectedEnd: getExpectedEnd(event, expectedStartState),
     plannedEnd,
   };
 }

apps/client/src/features/app-settings/panel/manage-panel/ManageRundowns.tsx

@@ -157,7 +157,7 @@ export default function ManageRundowns() {
                       </td>
                       <td>
                         <DropdownMenu
-                          render={<IconButton variant='ghosted-white' />}
+                          render={<IconButton variant='ghosted-white' data-testId='rundown_menu' />}
                           items={[
                             {
                               type: 'item',

apps/client/src/sentry.config.ts

@@ -82,5 +82,5 @@ export const initializeSentry = () => {
     },
   });
 
-  return Sentry.withSentryReactRouterV6Routing(Routes);
+  return Sentry.withSentryReactRouterV7Routing(Routes);
 };

apps/client/src/views/cuesheet/cuesheet-table/CuesheetTable.tsx

@@ -1,6 +1,6 @@
 import { useTableNav } from '@table-nav/react';
 import { ColumnDef, Table, getCoreRowModel, useReactTable } from '@tanstack/react-table';
-import { OntimeEntry, TimeField, isOntimeDelay, isOntimeGroup, isOntimeMilestone } from 'ontime-types';
+import { OntimeEntry, SupportedEntry, TimeField, isOntimeDelay, isOntimeGroup, isOntimeMilestone } from 'ontime-types';
 import { ComponentProps, ReactNode, memo, useCallback, useEffect, useMemo, useRef } from 'react';
 import {
   ContextProp,
@@ -20,6 +20,7 @@ import { usePersistedRundownOptions } from '../../../features/rundown/rundown.op
 import { useEventSelection } from '../../../features/rundown/useEventSelection';
 import { AppMode } from '../../../ontimeConfig';
 import { usePersistedCuesheetOptions } from '../cuesheet.options';
+import { useCuesheetPermissions } from '../useTablePermissions';
 import { CuesheetHeader, SortableCuesheetHeader } from './cuesheet-table-elements/CuesheetHeader';
 import DelayRow from './cuesheet-table-elements/DelayRow';
 import EventRow from './cuesheet-table-elements/EventRow';
@@ -62,7 +63,8 @@ export default function CuesheetTable({
   insertElement,
 }: CuesheetTableProps) {
   const { flatRundown, status, selectedEventId } = source;
-  const { updateEntry, updateTimer } = useEntryActionsContext();
+  const { updateEntry, updateTimer, addEntry } = useEntryActionsContext();
+  const canCreateEntries = useCuesheetPermissions((state) => state.canCreateEntries) && cuesheetMode === AppMode.Edit;
 
   const useOptions = tableRoot === 'editor' ? usePersistedRundownOptions : usePersistedCuesheetOptions;
   const optionsStore = useOptions();
@@ -202,8 +204,9 @@ export default function CuesheetTable({
       listeners,
       rows,
       table,
+      handleAddNew: canCreateEntries ? (type: SupportedEntry) => addEntry({ type }) : undefined,
     }),
-    [columnSizeVars, cursor, listeners, rows, table],
+    [columnSizeVars, cursor, listeners, rows, table, addEntry, canCreateEntries],
   );
 
   const computeItemKey = useCallback((_: number, item: ExtendedEntry) => item.id, []);
@@ -273,10 +276,13 @@ interface CuesheetVirtuosoContext {
   listeners: ReturnType<typeof useTableNav>['listeners'];
   rows: ReturnType<Table<ExtendedEntry>['getRowModel']>['rows'];
   table: Table<ExtendedEntry>;
+  handleAddNew?: (type: SupportedEntry) => void;
 }
 
-const EmptyPlaceholder = memo(function EmptyPlaceholder() {
-  return <EmptyTableBody text='No data in rundown' />;
+const EmptyPlaceholder = memo(function EmptyPlaceholder({
+  context,
+}: TableProps & ContextProp<CuesheetVirtuosoContext>) {
+  return <EmptyTableBody handleAddNew={context.handleAddNew} />;
 });
 
 const CuesheetTableElement = memo(function CuesheetTableElement({

apps/server/package.json

@@ -8,15 +8,15 @@
     "@googleapis/sheets": "^5.0.5",
     "cookie": "1.0.2",
     "cookie-parser": "1.4.7",
-    "cors": "2.8.5",
+    "cors": "2.8.6",
     "dotenv": "^16.0.1",
-    "express": "5.1.0",
-    "express-static-gzip": "3.0.0",
-    "express-validator": "7.2.1",
-    "fast-equals": "^5.0.1",
+    "express": "5.2.1",
+    "express-static-gzip": "3.0.1",
+    "express-validator": "7.3.2",
+    "fast-equals": "^6.0.0",
     "google-auth-library": "^9.4.2",
     "lowdb": "^7.0.1",
-    "multer": "2.1.0",
+    "multer": "2.2.0",
     "ontime-utils": "workspace:*",
     "osc-min": "2.1.2",
     "sanitize-filename": "^1.6.3",
@@ -24,9 +24,9 @@
     "xlsx": "^0.18.5"
   },
   "devDependencies": {
-    "@types/cookie-parser": "1.4.9",
+    "@types/cookie-parser": "1.4.10",
     "@types/cors": "2.8.19",
-    "@types/express": "5.0.3",
+    "@types/express": "5.0.6",
     "@types/multer": "2.1.0",
     "@types/node": "catalog:",
     "@types/ws": "^8.5.10",

apps/server/src/stores/__tests__/runtimeState.test.ts

@@ -245,6 +245,52 @@ describe('mutation on runtimeState', () => {
     expect(newState.offset.expectedRundownEnd).toBeNull();
   });
 
+  test('a countToEnd last event absorbs overtime into its fixed rundown end', async () => {
+    const tenAM = 10 * MILLIS_PER_HOUR;
+    const elevenAM = 11 * MILLIS_PER_HOUR;
+    const noon = 12 * MILLIS_PER_HOUR;
+
+    const entries = {
+      event1: {
+        ...mockEvent,
+        id: 'event1',
+        timeStart: tenAM,
+        timeEnd: elevenAM,
+        duration: MILLIS_PER_HOUR,
+        parent: null,
+      },
+      event2: {
+        ...mockEvent,
+        id: 'event2',
+        timeStart: elevenAM,
+        timeEnd: noon,
+        duration: MILLIS_PER_HOUR,
+        countToEnd: true,
+        linkStart: true,
+        parent: null,
+      },
+    };
+    const mockRundown = makeRundown({ entries, order: ['event1', 'event2'] });
+
+    await initRundown(mockRundown, {});
+    vi.runAllTimers();
+
+    const { metadata, rundown } = rundownCache.get();
+
+    // start event1 five minutes behind schedule
+    vi.setSystemTime('jan 1 10:05');
+    load(entries.event1, rundown, metadata);
+    start();
+    update();
+
+    const newState = getState();
+    expect(newState.offset.absolute).toBe(5 * MILLIS_PER_MINUTE);
+
+    // without countToEnd the rundown would end at noon + 5min, but the countToEnd
+    // event absorbs the overtime so the rundown is still expected to end at noon
+    expect(newState.offset.expectedRundownEnd).toBe(noon);
+  });
+
   test('resume restores currentDay from restore point', async () => {
     clearState();
     const mockRundown = makeRundown({
@@ -956,4 +1002,32 @@ describe('loadGroupFlagAndEnd()', () => {
       eventNow: rundown.entries[0],
     });
   });
+
+  test('a countToEnd event breaks the link chain for the events that follow it', () => {
+    // chain: A (loaded) -> B (countToEnd, flagged) -> C (linked, last event)
+    // the chain stays intact up to and including B, but breaks for C since it follows a countToEnd event
+    const rundown = makeRundown({
+      entries: {
+        A: makeOntimeEvent({ id: 'A', parent: null, linkStart: false, countToEnd: false, gap: 0 }),
+        B: makeOntimeEvent({ id: 'B', parent: null, linkStart: true, countToEnd: true, gap: 0, flag: true }),
+        C: makeOntimeEvent({ id: 'C', parent: null, linkStart: true, countToEnd: false, gap: 0 }),
+      },
+      order: ['A', 'B', 'C'],
+    });
+
+    const state = {
+      groupNow: null,
+      eventNow: rundown.entries.A,
+      rundown: { actualGroupStart: null },
+    } as RuntimeState;
+
+    const metadata = { playableEventOrder: ['A', 'B', 'C'], flags: ['B'] } as RundownMetadata;
+
+    loadGroupFlagAndEnd(rundown, metadata, 0, state);
+
+    // the flag (B) is still part of the chain
+    expect(state._flag).toMatchObject({ event: rundown.entries.B, isLinkedToLoaded: true });
+    // the rundown end (C) follows the countToEnd event, so the chain is broken
+    expect(state._end).toMatchObject({ event: rundown.entries.C, isLinkedToLoaded: false });
+  });
 });

apps/server/src/stores/runtimeState.ts

@@ -23,6 +23,7 @@ import {
   calculateDuration,
   checkIsNow,
   dayInMs,
+  getExpectedEnd,
   getExpectedStart,
   getLastEventNormal,
   isPlaybackActive,
@@ -836,8 +837,8 @@ function getExpectedTimes(state = runtimeState) {
     const { _group } = state;
     if (_group !== null) {
       const { event: lastEvent, accumulatedGap, isLinkedToLoaded } = _group;
-      const lastEventExpectedStart = getExpectedStart(lastEvent, {
-        currentDay: state.rundown.currentDay!,
+      state.offset.expectedGroupEnd = getExpectedEnd(lastEvent, {
+        currentDay: state.rundown.currentDay ?? 0,
         totalGap: accumulatedGap,
         isLinkedToLoaded,
         mode: offset.mode,
@@ -845,7 +846,6 @@ function getExpectedTimes(state = runtimeState) {
         plannedStart,
         actualStart,
       });
-      state.offset.expectedGroupEnd = lastEventExpectedStart + lastEvent.duration;
     }
   }
 
@@ -868,8 +868,8 @@ function getExpectedTimes(state = runtimeState) {
 
   if (state._end) {
     const { event, accumulatedGap, isLinkedToLoaded } = state._end;
-    const expectedStart = getExpectedStart(event, {
-      currentDay: state.rundown.currentDay!,
+    state.offset.expectedRundownEnd = getExpectedEnd(event, {
+      currentDay: state.rundown.currentDay ?? 0,
       totalGap: accumulatedGap,
       isLinkedToLoaded,
       mode: offset.mode,
@@ -877,7 +877,6 @@ function getExpectedTimes(state = runtimeState) {
       plannedStart,
       actualStart,
     });
-    state.offset.expectedRundownEnd = expectedStart + event.duration;
   }
 }
 
@@ -920,6 +919,8 @@ export function loadGroupFlagAndEnd(
 
   let accumulatedGap = 0;
   let isLinkedToLoaded = true;
+  // a countToEnd event absorbs overtime and breaks the chain
+  let previousWasCountToEnd = false;
 
   for (let idx = currentIndex; idx < playableEventOrder.length; idx++) {
     const entry = entries[playableEventOrder[idx]];
@@ -928,7 +929,7 @@ export function loadGroupFlagAndEnd(
       if (idx !== currentIndex) {
         // we only accumulate data after the loaded event
         accumulatedGap += entry.gap;
-        isLinkedToLoaded = isLinkedToLoaded && entry.linkStart;
+        isLinkedToLoaded = isLinkedToLoaded && entry.linkStart && !previousWasCountToEnd;
 
         // and the loaded event is not allowed to be the next flag
         if (!foundFlag && metadata.flags.includes(entry.id)) {
@@ -942,6 +943,8 @@ export function loadGroupFlagAndEnd(
         foundGroupEnd = true;
         state._group = { event: lastEventInGroup, isLinkedToLoaded, accumulatedGap };
       }
+
+      previousWasCountToEnd = entry.countToEnd;
     }
   }
 

e2e/tests/features/202-cuesheet.spec.ts

@@ -100,3 +100,27 @@ test('cuesheet datagrid keeps keyboard focus flow while editing text cells', asy
   await expect(cueEditor).not.toBeFocused();
   await expect(cueEditor).toHaveValue(cueBeforeCancel);
 });
+
+test('cuesheet background edit from empty state', async ({ page }) => {
+  // create an empty rundown
+  await page.goto('/editor');
+  await page.getByRole('button', { name: 'Toggle settings' }).click();
+  await page.getByRole('button', { name: 'Manage rundowns' }).click();
+  await page.getByRole('button', { name: 'New' }).nth(1).click();
+  const emptyName = `empty-${Date.now()}`;
+  await page.getByRole('textbox', { name: 'Rundown title' }).fill(emptyName);
+  await page.getByRole('button', { name: 'Create rundown' }).click();
+
+  // edit it in the cuesheet
+  await page.getByRole('row', { name: '0 empty-' }).getByTestId('rundown_menu').click();
+  await page.getByText('Edit in cuesheet').click();
+
+  // expect to see and empty screen
+  await expect(page.getByRole('button', { name: 'Create Event' })).toBeVisible();
+
+  // create 1 event
+  await page.getByRole('button', { name: 'Create Event' }).click();
+
+  // and expect to find it
+  await expect(page.getByTestId('cuesheet-event')).toBeVisible();
+});

package.json

@@ -55,7 +55,7 @@
   "devEngines": {
     "runtime": {
       "name": "node",
-      "version": "22.22.2"
+      "version": "22.22.3"
     }
   }
 }

packages/utils/index.ts

@@ -80,7 +80,7 @@ export { validateEndAction, validateTimerType } from './src/validate-events/vali
 
 // feature business logic
 
-export { getExpectedStart } from './src/date-utils/getExpectedStart.js';
+export { getExpectedStart, getExpectedEnd } from './src/date-utils/getExpected.js';
 
 // feature business logic - rundown
 export { checkIsNow } from './src/date-utils/checkIsNow.js';

packages/utils/src/date-utils/getExpected.test.ts

@@ -1,7 +1,7 @@
 import { Day, OffsetMode } from 'ontime-types';
 
 import { MILLIS_PER_HOUR, dayInMs } from './conversionUtils';
-import { getExpectedStart } from './getExpectedStart';
+import { getExpectedEnd, getExpectedStart } from './getExpected';
 
 describe('getExpectedStart()', () => {
   describe('Absolute offset mode', () => {
@@ -315,3 +315,123 @@ describe('getExpectedStart()', () => {
     expect(getExpectedStart(testEvent, { ...testState, currentDay: 0 })).toBe(23 * MILLIS_PER_HOUR + 5);
   });
 });
+
+describe('getExpectedEnd()', () => {
+  const baseState = {
+    currentDay: 0,
+    totalGap: 0,
+    mode: OffsetMode.Absolute,
+    actualStart: null,
+    plannedStart: null,
+    isLinkedToLoaded: true,
+  };
+
+  test('a regular event ends at its expected start plus duration', () => {
+    const testEvent = {
+      timeStart: 100,
+      duration: 50,
+      delay: 0,
+      dayOffset: 0 as Day,
+      countToEnd: false,
+    };
+
+    // on schedule
+    expect(getExpectedEnd(testEvent, { ...baseState, offset: 0 })).toBe(150);
+    // running 20 behind pushes the end out
+    expect(getExpectedEnd(testEvent, { ...baseState, offset: 20 })).toBe(170);
+  });
+
+  test('a countToEnd event pins to the planned end while in overtime', () => {
+    const testEvent = {
+      timeStart: 100,
+      duration: 50,
+      delay: 0,
+      dayOffset: 0 as Day,
+      countToEnd: true,
+    };
+
+    // overtime would otherwise push the end to 170, but countToEnd absorbs it and pins to 150
+    expect(getExpectedEnd(testEvent, { ...baseState, offset: 20 })).toBe(150);
+  });
+
+  test('a countToEnd event pins to the planned end while ahead of schedule', () => {
+    const testEvent = {
+      timeStart: 100,
+      duration: 50,
+      delay: 0,
+      dayOffset: 0 as Day,
+      countToEnd: true,
+    };
+
+    // ahead of schedule the start moves earlier (90) but the end stays pinned to 150
+    expect(getExpectedEnd(testEvent, { ...baseState, offset: -10 })).toBe(150);
+  });
+
+  test('an overnight countToEnd event returns a normalised end', () => {
+    // event starts at 23:00 and counts to 01:00 the next day -> duration spans midnight
+    const timeStart = 23 * MILLIS_PER_HOUR;
+    const duration = 2 * MILLIS_PER_HOUR;
+    const testEvent = {
+      timeStart,
+      duration,
+      delay: 0,
+      dayOffset: 0 as Day,
+      countToEnd: true,
+    };
+
+    expect(getExpectedEnd(testEvent, { ...baseState, offset: 0 })).toBe(timeStart + duration);
+  });
+
+  test('a countToEnd event drifts when the start is compromised', () => {
+    const testEvent = {
+      timeStart: 100,
+      duration: 50,
+      delay: 0,
+      dayOffset: 0 as Day,
+      countToEnd: true,
+    };
+
+    // the offset pushes the start (160) past the scheduled end (150) so it can no longer
+    // finish on schedule - the end follows the compromised start
+    expect(getExpectedEnd(testEvent, { ...baseState, offset: 60 })).toBe(160);
+  });
+
+  test('a countToEnd event on a later day keeps the day offset on the end', () => {
+    const testEvent = {
+      timeStart: 100,
+      duration: 50,
+      delay: 0,
+      dayOffset: 1 as Day,
+      countToEnd: true,
+    };
+
+    // the scheduled end must include the day offset (delayedStart + dayInMs + duration),
+    // not collapse to the day-shifted start
+    expect(getExpectedEnd(testEvent, { ...baseState, currentDay: 0, offset: 0 })).toBe(150 + dayInMs);
+    // when the running event is already on the same day, no extra day is added
+    expect(getExpectedEnd({ ...testEvent, dayOffset: 0 as Day }, { ...baseState, currentDay: 0, offset: 0 })).toBe(150);
+  });
+
+  test('a countToEnd event is anchored to its wall-clock end in relative mode', () => {
+    const testEvent = {
+      timeStart: 100,
+      duration: 50,
+      delay: 0,
+      dayOffset: 0 as Day,
+      countToEnd: true,
+    };
+
+    const relativeState = {
+      ...baseState,
+      mode: OffsetMode.Relative,
+      actualStart: 30,
+      plannedStart: 0,
+      offset: 0,
+    };
+
+    // a regular event in the same state is shifted by the relative-start offset to 180
+    expect(getExpectedEnd({ ...testEvent, countToEnd: false }, relativeState)).toBe(180);
+    // the countToEnd event stays pinned to its wall-clock end (150), not shifted
+    expect(getExpectedEnd(testEvent, relativeState)).toBe(150);
+  });
+});

packages/utils/src/date-utils/getExpected.ts

@@ -8,7 +8,6 @@ import { dayInMs } from './conversionUtils.js';
  * @param currentDay the day offset of the currently running event
  * @param totalGap accumulated gap from the current event
  * @param isLinkedToLoaded is this event part of a chain linking back to the current loaded event
- * @param clock
  * @param offset
  * @returns
  */
@@ -60,3 +59,39 @@ export function getExpectedStart(
   const offsetStartTimeBufferedByGaps = offsetStartTime - totalGap;
   return offsetStartTimeBufferedByGaps;
 }
+
+/**
+ * @param event the event that we are counting to
+ * @param currentDay the day offset of the currently running event
+ * @param totalGap accumulated gap from the current event
+ * @param isLinkedToLoaded is this event part of a chain linking back to the current loaded event
+ * @param offset
+ * @returns
+ */
+export function getExpectedEnd(
+  event: Pick<OntimeEvent, 'timeStart' | 'dayOffset' | 'delay' | 'duration' | 'countToEnd'>,
+  state: {
+    currentDay: number; // the current day from the rundown
+    totalGap: number;
+    isLinkedToLoaded: boolean;
+    offset: number;
+    mode: OffsetMode;
+    actualStart: MaybeNumber;
+    plannedStart: MaybeNumber;
+  },
+): number {
+  // expected start encodes the offset from current delays
+  const expectedStart = getExpectedStart(event, state);
+
+  // count to end events should finish on schedule unlesss the start is compromised
+  if (event.countToEnd) {
+    // the scheduled end, normalised to the same day-space as expectedStart
+    // (a raw timeStart + duration would miss the day offset on multi-day rundowns)
+    const delayedStart = Math.max(0, event.timeStart + event.delay);
+    const relativeDayOffset = event.dayOffset - state.currentDay;
+    const scheduledEnd = delayedStart + relativeDayOffset * dayInMs + event.duration;
+    return Math.max(expectedStart, scheduledEnd);
+  }
+
+  return expectedStart + event.duration;
+}