refactor: move totalDelay to _rundown

apps/client/src/common/hooks/useSocket.ts

@@ -1,4 +1,4 @@
-import { RuntimeStore, SimpleDirection, SimplePlayback, TimerMessage } from 'ontime-types';
+import { OffsetMode, RuntimeStore, SimpleDirection, SimplePlayback, TimerMessage } from 'ontime-types';
 
 import { useRuntimeStore } from '../stores/runtime';
 import { socketSendJson } from '../utils/socket';
@@ -160,7 +160,7 @@ export const useRuntimePlaybackOverview = createSelector((state: RuntimeStore) =
 
   numEvents: state.runtime.numEvents,
   selectedEventIndex: state.runtime.selectedEventIndex,
-  offset: state.runtime.offset,
+  offset: state.runtime.offsetMode === OffsetMode.Absolute ? state.runtime.offset : state.runtime.relativeOffset,
 
   currentBlock: state.currentBlock,
 }));
@@ -172,8 +172,11 @@ export const useTimelineStatus = createSelector((state: RuntimeStore) => ({
 
 export const useTimeUntilData = createSelector((state: RuntimeStore) => ({
   clock: state.clock,
-  offset: state.runtime.offset,
+  offset: state.runtime.offsetMode === OffsetMode.Absolute ? state.runtime.offset : state.runtime.relativeOffset,
+  offsetMode: state.runtime.offsetMode,
   currentDay: state.eventNow?.dayOffset ?? 0, //The day of the currently running event
+  actualStart: state.runtime.actualStart,
+  plannedStart: state.runtime.plannedStart,
 }));
 
 export const useRuntimeOffset = createSelector((state: RuntimeStore) => ({
@@ -189,6 +192,12 @@ export const useIsOnline = createSelector((state: RuntimeStore) => ({
   isOnline: state.ping > 0,
 }));
 
+export const useOffsetMode = createSelector((state: RuntimeStore) => ({
+  offsetMode: state.runtime.offsetMode,
+}));
+
+export const setOffsetMode = (payload: OffsetMode) => socketSendJson('offsetmode', payload);
+
 export const usePlayback = () => {
   const featureSelector = (state: RuntimeStore) => ({
     playback: state.timer.playback,

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

@@ -1,3 +1,6 @@
+import { OffsetMode } from 'ontime-types';
+import { dayInMs } from 'ontime-utils';
+
 import { calculateTimeUntilStart, formatTime, nowInMillis } from '../time';
 
 describe('nowInMillis()', () => {
@@ -40,82 +43,265 @@ describe('formatTime()', () => {
 });
 
 describe('calculateTimeUntilStart()', () => {
-  test('ontime', () => {
+  describe('Absolute offset mode', () => {
+    test('ontime', () => {
+      const test = {
+        timeStart: 100,
+        dayOffset: 0,
+        delay: 0,
+        currentDay: 0,
+        totalGap: 0,
+        clock: 90,
+        offset: 0,
+        offsetMode: OffsetMode.Absolute,
+        actualStart: null,
+        plannedStart: null,
+      };
+
+      expect(calculateTimeUntilStart({ ...test, isLinkedToLoaded: false })).toBe(10);
+      expect(calculateTimeUntilStart({ ...test, isLinkedToLoaded: true })).toBe(10);
+    });
+
+    test('running behind', () => {
+      const test = {
+        timeStart: 100,
+        dayOffset: 0,
+        delay: 0,
+        currentDay: 0,
+        totalGap: 0,
+        clock: 90,
+        offset: -20,
+        offsetMode: OffsetMode.Absolute,
+        actualStart: null,
+        plannedStart: null,
+      };
+
+      expect(calculateTimeUntilStart({ ...test, isLinkedToLoaded: false })).toBe(30);
+      expect(calculateTimeUntilStart({ ...test, isLinkedToLoaded: true })).toBe(30);
+    });
+
+    test('running ahead', () => {
+      const test = {
+        timeStart: 100,
+        dayOffset: 0,
+        delay: 0,
+        currentDay: 0,
+        totalGap: 0,
+        clock: 80,
+        offset: 10,
+        offsetMode: OffsetMode.Absolute,
+        actualStart: null,
+        plannedStart: null,
+      };
+
+      expect(calculateTimeUntilStart({ ...test, isLinkedToLoaded: false })).toBe(20); // <-- when running ahead the unlinked timer stays put
+      expect(calculateTimeUntilStart({ ...test, isLinkedToLoaded: true })).toBe(10);
+    });
+
+    test('running behind with enough gaps', () => {
+      const test = {
+        timeStart: 100,
+        dayOffset: 0,
+        delay: 0,
+        currentDay: 0,
+        totalGap: 20,
+        clock: 50,
+        offset: -20,
+        offsetMode: OffsetMode.Absolute,
+        actualStart: null,
+        plannedStart: null,
+      };
+
+      expect(calculateTimeUntilStart({ ...test, isLinkedToLoaded: false })).toBe(50); // <-- when gap is enough to compensate for the running behind
+      expect(calculateTimeUntilStart({ ...test, isLinkedToLoaded: true })).toBe(70); // This should not be possible
+    });
+
+    test('running behind with too little gaps', () => {
+      const test = {
+        timeStart: 100,
+        dayOffset: 0,
+        delay: 0,
+        currentDay: 0,
+        totalGap: 10,
+        clock: 50,
+        offset: -20,
+        offsetMode: OffsetMode.Absolute,
+        actualStart: 0,
+        plannedStart: 0,
+      };
+
+      expect(calculateTimeUntilStart({ ...test, isLinkedToLoaded: false })).toBe(60); // <-- when gap is not enough to compensate for the running behind it absorbs at much as possible
+      expect(calculateTimeUntilStart({ ...test, isLinkedToLoaded: true })).toBe(70); // This should not be possible
+    });
+  });
+
+  describe('Relative offset mode', () => {
+    test('basic function', () => {
+      const test = {
+        timeStart: 0,
+        dayOffset: 0,
+        delay: 0,
+        currentDay: 0,
+        totalGap: 0,
+        clock: 100,
+        actualStart: 100,
+        plannedStart: 0,
+        offset: 0, // relative
+        // offset: -100, // absolute
+        offsetMode: OffsetMode.Relative,
+      };
+
+      const timeStartEvent2 = 10;
+      const timeStartEvent3 = 20;
+
+      //event 1 is the currently running event
+
+      //event 2
+      expect(calculateTimeUntilStart({ ...test, timeStart: timeStartEvent2, isLinkedToLoaded: true })).toBe(10);
+      expect(calculateTimeUntilStart({ ...test, timeStart: timeStartEvent2, isLinkedToLoaded: false })).toBe(10);
+
+      //event 3
+      expect(calculateTimeUntilStart({ ...test, timeStart: timeStartEvent3, isLinkedToLoaded: true })).toBe(20);
+      expect(calculateTimeUntilStart({ ...test, timeStart: timeStartEvent3, isLinkedToLoaded: false })).toBe(20);
+
+      // When clock advances by 5ms, time until start should decrease by 5ms
+      test.clock = 105;
+
+      //event 2
+      expect(calculateTimeUntilStart({ ...test, timeStart: timeStartEvent2, isLinkedToLoaded: true })).toBe(5);
+      expect(calculateTimeUntilStart({ ...test, timeStart: timeStartEvent2, isLinkedToLoaded: false })).toBe(5);
+
+      //event 3
+      expect(calculateTimeUntilStart({ ...test, timeStart: timeStartEvent3, isLinkedToLoaded: true })).toBe(15);
+      expect(calculateTimeUntilStart({ ...test, timeStart: timeStartEvent3, isLinkedToLoaded: false })).toBe(15);
+    });
+
+    test('gaps', () => {
+      const test = {
+        timeStart: 20,
+        dayOffset: 0,
+        delay: 0,
+        currentDay: 0,
+        totalGap: 10,
+        clock: 100,
+        actualStart: 100,
+        plannedStart: 0,
+        offset: 0, // relative
+        // offset: -100, // absolute
+        offsetMode: OffsetMode.Relative,
+      };
+
+      expect(calculateTimeUntilStart({ ...test, isLinkedToLoaded: true })).toBe(20);
+      expect(calculateTimeUntilStart({ ...test, isLinkedToLoaded: false })).toBe(20);
+
+      // When clock advances by 5ms, time until start should decrease by 5ms
+      test.clock = 105;
+      expect(calculateTimeUntilStart({ ...test, isLinkedToLoaded: true })).toBe(15);
+      expect(calculateTimeUntilStart({ ...test, isLinkedToLoaded: false })).toBe(15);
+    });
+
+    test('added/remove time', () => {
+      const test = {
+        timeStart: 20,
+        dayOffset: 0,
+        delay: 0,
+        currentDay: 0,
+        totalGap: 0,
+        clock: 100,
+        actualStart: 100,
+        plannedStart: 0,
+        offset: 0, // relative
+        // offset: -100, // absolute
+        offsetMode: OffsetMode.Relative,
+      };
+
+      expect(calculateTimeUntilStart({ ...test, isLinkedToLoaded: true })).toBe(20);
+      expect(calculateTimeUntilStart({ ...test, isLinkedToLoaded: false })).toBe(20);
+
+      test.offset = 5; // remove 5 with addtime - we are ahead of time
+
+      expect(calculateTimeUntilStart({ ...test, isLinkedToLoaded: true })).toBe(15);
+      expect(calculateTimeUntilStart({ ...test, isLinkedToLoaded: false })).toBe(20); // unlocked evets will stay on schedule
+
+      test.offset = -5; // add 5 with addtime - we are behind
+
+      expect(calculateTimeUntilStart({ ...test, isLinkedToLoaded: true })).toBe(25);
+      expect(calculateTimeUntilStart({ ...test, isLinkedToLoaded: false })).toBe(25);
+    });
+
+    test('next day', () => {
+      const test = {
+        // timeStart: 10,
+        // dayOffset: 0,
+        delay: 0,
+        currentDay: 0,
+        // totalGap: 0,
+        clock: 100,
+        actualStart: 100,
+        plannedStart: 0,
+        offset: 0, // relative
+        // offset: -100, // absolute
+        offsetMode: OffsetMode.Relative,
+      };
+
+      // this event will start the current day
+      expect(
+        calculateTimeUntilStart({
+          ...test,
+          timeStart: 10,
+          dayOffset: 0,
+          totalGap: 0,
+          isLinkedToLoaded: false,
+        }),
+      ).toBe(10);
+
+      // this event will start the next day
+      // in absolute mode this would start in dayInMs - 100 since the gap would compensate
+      // but in relative mode with and actual start that is 100 offset it starts in dayInMs
+      expect(
+        calculateTimeUntilStart({
+          ...test,
+          timeStart: 0,
+          dayOffset: 1,
+          totalGap: dayInMs - 20,
+          isLinkedToLoaded: false,
+        }),
+      ).toBe(dayInMs);
+
+      // advancing 100ms
+      test.clock = 200;
+
+      expect(
+        calculateTimeUntilStart({
+          ...test,
+          timeStart: 0,
+          dayOffset: 1,
+          totalGap: dayInMs - 20,
+          isLinkedToLoaded: false,
+        }),
+      ).toBe(dayInMs - 100);
+    });
+  });
+
+  test('overlap with negative total gap', () => {
     const test = {
-      timeStart: 100,
+      // timeStart: 20,
       dayOffset: 0,
       delay: 0,
       currentDay: 0,
-      totalGap: 0,
-      clock: 90,
-      offset: 0,
+      // totalGap: 10,
+      clock: 100,
+      actualStart: 100,
+      plannedStart: 0,
+      offset: 0, // relative
+      // offset: -100, // absolute
+      offsetMode: OffsetMode.Relative,
+      isLinkedToLoaded: false,
     };
 
-    expect(calculateTimeUntilStart({ ...test, isLinkedToLoaded: false })).toBe(10);
-    expect(calculateTimeUntilStart({ ...test, isLinkedToLoaded: true })).toBe(10);
+    // the overlap will be pushed out to the expected available time
+    expect(calculateTimeUntilStart({ ...test, timeStart: 5, totalGap: -5 })).toBe(10);
+
+    test.clock = 105;
   });
-
-  test('running behind', () => {
-    const test = {
-      timeStart: 100,
-      dayOffset: 0,
-      delay: 0,
-      currentDay: 0,
-      totalGap: 0,
-      clock: 90,
-      offset: -20,
-    };
-
-    expect(calculateTimeUntilStart({ ...test, isLinkedToLoaded: false })).toBe(30);
-    expect(calculateTimeUntilStart({ ...test, isLinkedToLoaded: true })).toBe(30);
-  });
-
-  test('running ahead', () => {
-    const test = {
-      timeStart: 100,
-      dayOffset: 0,
-      delay: 0,
-      currentDay: 0,
-      totalGap: 0,
-      clock: 80,
-      offset: 10,
-    };
-
-    expect(calculateTimeUntilStart({ ...test, isLinkedToLoaded: false })).toBe(20); // <-- when running ahead the unlinked timer stays put
-    expect(calculateTimeUntilStart({ ...test, isLinkedToLoaded: true })).toBe(10);
-  });
-
-  test('running behind with enough gaps', () => {
-    const test = {
-      timeStart: 100,
-      dayOffset: 0,
-      delay: 0,
-      currentDay: 0,
-      totalGap: 20,
-      clock: 50,
-      offset: -20,
-    };
-
-    expect(calculateTimeUntilStart({ ...test, isLinkedToLoaded: false })).toBe(50);
-    expect(calculateTimeUntilStart({ ...test, isLinkedToLoaded: true })).toBe(70); // This should not be possible
-  });
-
-  test('running behind with to little gaps', () => {
-    const test = {
-      timeStart: 100,
-      dayOffset: 0,
-      delay: 0,
-      currentDay: 0,
-      totalGap: 10,
-      clock: 50,
-      offset: -20,
-    };
-
-    expect(calculateTimeUntilStart({ ...test, isLinkedToLoaded: false })).toBe(60);
-    expect(calculateTimeUntilStart({ ...test, isLinkedToLoaded: true })).toBe(70); // This should not be possible
-  });
-
-  //TODO: more indepth testing,
-  // including day offset handling
-  // and more?
 });

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

@@ -1,4 +1,4 @@
-import { MaybeNumber, OntimeEvent, Settings, TimeFormat } from 'ontime-types';
+import { MaybeNumber, OffsetMode, OntimeEvent, Settings, TimeFormat } from 'ontime-types';
 import { dayInMs, formatFromMillis, MILLIS_PER_HOUR, MILLIS_PER_MINUTE, MILLIS_PER_SECOND } from 'ontime-utils';
 
 import { FORMAT_12, FORMAT_24 } from '../../viewerConfig';
@@ -140,8 +140,8 @@ export function useTimeUntilStart(
     isLinkedToLoaded: boolean;
   },
 ): number {
-  const { offset, clock, currentDay } = useTimeUntilData();
-  return calculateTimeUntilStart({ ...data, currentDay, clock, offset });
+  const { offset, clock, currentDay, offsetMode, actualStart, plannedStart } = useTimeUntilData();
+  return calculateTimeUntilStart({ ...data, currentDay, clock, offset, offsetMode, actualStart, plannedStart });
 }
 
 /**
@@ -160,9 +160,24 @@ export function calculateTimeUntilStart(
     isLinkedToLoaded: boolean;
     clock: number;
     offset: number;
+    offsetMode: OffsetMode;
+    actualStart: MaybeNumber;
+    plannedStart: MaybeNumber;
   },
 ): number {
-  const { timeStart, dayOffset, currentDay, totalGap, isLinkedToLoaded, clock, offset, delay } = data;
+  const {
+    timeStart,
+    dayOffset,
+    currentDay,
+    totalGap,
+    isLinkedToLoaded,
+    clock,
+    offset,
+    delay,
+    offsetMode,
+    actualStart,
+    plannedStart,
+  } = data;
 
   //How many days from the currently running event to this one
   const relativeDayOffset = dayOffset - currentDay;
@@ -172,20 +187,23 @@ export function calculateTimeUntilStart(
   //The normalised start time of this event relative to the currently running event
   const normalisedTimeStart = delayedStart + relativeDayOffset * dayInMs;
 
-  const offsetTimestart = normalisedTimeStart - offset;
-  const offsetTimeUntil = offsetTimestart - clock;
+  let relativeStartOffset = 0;
+
+  if (offsetMode === OffsetMode.Relative) {
+    relativeStartOffset = (actualStart ?? 0) - (plannedStart ?? 0);
+  }
+
+  const scheduledTimeUntil = normalisedTimeStart - clock + relativeStartOffset;
+
+  const offsetTimeUntil = scheduledTimeUntil - offset;
 
   if (isLinkedToLoaded) {
     //if we are directly linked back to the loaded event we just follow the offset
     return offsetTimeUntil;
   }
 
-  const scheduledTimeUntil = normalisedTimeStart - clock;
-
-  const isAheadOfSchedule = offset >= 0;
-  const gapsCanCompensadeForOffset = totalGap + offset >= 0;
-
-  if (isAheadOfSchedule || gapsCanCompensadeForOffset) {
+  const gapsCanCompensateForOffset = totalGap + offset >= 0;
+  if (gapsCanCompensateForOffset) {
     // if we are ahead of schedule or the gap can compensate for the amount we are behind then expect to start at the scheduled time
     return scheduledTimeUntil;
   }

apps/client/src/features/overview/Overview.tsx

@@ -170,7 +170,7 @@ function RuntimeOverview() {
 
   return (
     <>
-      <TimeColumn label='Offset' value={offsetText} className={offsetClasses} />
+      <TimeColumn label='Offset' value={offsetText} className={offsetClasses} testId='offset' />
       <TimeColumn label='Time now' value={formatedTime(clock)} />
     </>
   );

apps/client/src/features/overview/composite/TimeLayout.tsx

@@ -10,13 +10,16 @@ interface TimeLayoutProps {
   muted?: boolean;
   daySpan?: number;
   className?: string;
+  testId?: string;
 }
 
-export function TimeColumn({ label, value, muted, className }: TimeLayoutProps) {
+export function TimeColumn({ label, value, muted, className, testId }: TimeLayoutProps) {
   return (
     <div className={style.column}>
       <span className={style.label}>{label}</span>
-      <span className={cx([style.clock, muted && style.muted, className])}>{value}</span>
+      <span className={cx([style.clock, muted && style.muted, className])} data-testid={testId}>
+        {value}
+      </span>
     </div>
   );
 }

apps/client/src/features/rundown/rundown-header/RundownHeader.tsx

@@ -1,5 +1,7 @@
 import { Button, ButtonGroup } from '@chakra-ui/react';
+import { OffsetMode } from 'ontime-types';
 
+import { setOffsetMode, useOffsetMode } from '../../../common/hooks/useSocket';
 import { AppMode, useAppMode } from '../../../common/stores/appModeStore';
 
 import RundownMenu from './RundownMenu';
@@ -12,6 +14,8 @@ export default function RundownHeader() {
   const setRunMode = () => setAppMode(AppMode.Run);
   const setEditMode = () => setAppMode(AppMode.Edit);
 
+  const { offsetMode } = useOffsetMode();
+
   return (
     <div className={style.header}>
       <ButtonGroup isAttached>
@@ -22,6 +26,22 @@ export default function RundownHeader() {
           Edit
         </Button>
       </ButtonGroup>
+      <ButtonGroup isAttached>
+        <Button
+          size='sm'
+          variant={offsetMode === OffsetMode.Absolute ? 'ontime-filled' : 'ontime-subtle'}
+          onClick={() => setOffsetMode(OffsetMode.Absolute)}
+        >
+          Absolute
+        </Button>
+        <Button
+          size='sm'
+          variant={offsetMode === OffsetMode.Relative ? 'ontime-filled' : 'ontime-subtle'}
+          onClick={() => setOffsetMode(OffsetMode.Relative)}
+        >
+          Relative
+        </Button>
+      </ButtonGroup>
       <RundownMenu />
     </div>
   );

apps/server/src/api-integration/integration.controller.ts

@@ -1,4 +1,4 @@
-import { MessageState, OntimeEvent, SimpleDirection, SimplePlayback } from 'ontime-types';
+import { MessageState, OffsetMode, OntimeEvent, SimpleDirection, SimplePlayback } from 'ontime-types';
 import { MILLIS_PER_HOUR, MILLIS_PER_SECOND } from 'ontime-utils';
 
 import { DeepPartial } from 'ts-essentials';
@@ -17,6 +17,7 @@ import { throttle } from '../utils/throttle.js';
 import { willCauseRegeneration } from '../services/rundown-service/rundownCacheUtils.js';
 
 import { handleLegacyMessageConversion } from './integration.legacy.js';
+import { coerceEnum } from '../utils/coerceType.js';
 
 const throttledUpdateEvent = throttle(updateEvent, 20);
 let lastRequest: Date | null = null;
@@ -286,6 +287,11 @@ const actionHandlers: Record<string, ActionHandler> = {
 
     throw new Error('No matching method provided');
   },
+  offsetmode: (payload) => {
+    const mode = coerceEnum<OffsetMode>(payload, OffsetMode);
+    runtimeService.setOffsetMode(mode);
+    return { payload: 'success' };
+  },
 };
 
 /**

apps/server/src/services/__tests__/timerUtils.test.ts

@@ -4,6 +4,7 @@ import { EndAction, Playback, TimeStrategy, TimerPhase, TimerType } from 'ontime
 import {
   getCurrent,
   getExpectedFinish,
+  getRelativeOffset,
   getRuntimeOffset,
   getTimerPhase,
   normaliseEndTime,
@@ -1046,6 +1047,84 @@ describe('getRuntimeOffset()', () => {
   });
 });
 
+describe('getRelativeOffset()', () => {
+  it('relative offset is 0 when starting at the planed time', () => {
+    const state = {
+      eventNow: {
+        id: '1',
+        timeStart: 150,
+      },
+      timer: {
+        startedAt: 150,
+        addedTime: 0,
+        current: 0,
+      },
+      _timer: {
+        pausedAt: null,
+      },
+      runtime: {
+        actualStart: 150,
+        plannedStart: 150,
+      },
+    } as RuntimeState;
+
+    state.runtime.offset = getRuntimeOffset(state);
+    expect(state.runtime.offset).toBe(0);
+    const relativeOffsetoffset = getRelativeOffset(state);
+    expect(relativeOffsetoffset).toBe(0);
+  });
+  it('relative offset is 0 when starting after the planed time', () => {
+    const state = {
+      eventNow: {
+        id: '1',
+        timeStart: 100,
+      },
+      timer: {
+        startedAt: 150,
+        addedTime: 0,
+        current: 0,
+      },
+      _timer: {
+        pausedAt: null,
+      },
+      runtime: {
+        actualStart: 150,
+        plannedStart: 100,
+      },
+    } as RuntimeState;
+
+    state.runtime.offset = getRuntimeOffset(state);
+    expect(state.runtime.offset).toBe(-50);
+    const relativeOffsetoffset = getRelativeOffset(state);
+    expect(relativeOffsetoffset).toBe(0);
+  });
+  it('relative offset is 0 when starting before the planed time', () => {
+    const state = {
+      eventNow: {
+        id: '1',
+        timeStart: 150,
+      },
+      timer: {
+        startedAt: 100,
+        addedTime: 0,
+        current: 0,
+      },
+      _timer: {
+        pausedAt: null,
+      },
+      runtime: {
+        actualStart: 100,
+        plannedStart: 150,
+      },
+    } as RuntimeState;
+
+    state.runtime.offset = getRuntimeOffset(state);
+    expect(state.runtime.offset).toBe(50);
+    const relativeOffsetoffset = getRelativeOffset(state);
+    expect(relativeOffsetoffset).toBe(0);
+  });
+});
+
 describe('getTimerPhase()', () => {
   it('should be None if the timer is not running', () => {
     const state = {
@@ -1169,9 +1248,11 @@ describe('getTimerPhase()', () => {
       },
       _timer: {
         forceFinish: null,
-        totalDelay: 0,
         pausedAt: null,
       },
+      _rundown: {
+        totalDelay: 0,
+      },
     } as RuntimeState;
 
     const phase = getTimerPhase(state);
@@ -1208,9 +1289,11 @@ describe('getTimerPhase()', () => {
       },
       _timer: {
         forceFinish: null,
-        totalDelay: 0,
         pausedAt: null,
       },
+      _rundown: {
+        totalDelay: 0,
+      },
     } as RuntimeState;
 
     const phase = getTimerPhase(state);

apps/server/src/services/runtime-service/RuntimeService.ts

@@ -4,6 +4,7 @@ import {
   isPlayableEvent,
   LogOrigin,
   MaybeNumber,
+  OffsetMode,
   OntimeEvent,
   Playback,
   TimerLifeCycle,
@@ -68,6 +69,11 @@ class RuntimeService {
     RuntimeService.previousState = {} as RuntimeState;
   }
 
+  @broadcastResult
+  setOffsetMode(mode: OffsetMode) {
+    runtimeState.setOffsetMode(mode);
+  }
+
   /**
    * Checks result of an update and notifies integrations as needed
    * This is the only exception of a private method that has broadcast result
@@ -697,11 +703,14 @@ function broadcastResult(_target: any, _propertyKey: string, descriptor: Propert
     // for the very fist run there will be nothing in the previousState so we force an update
     const justStarted = !RuntimeService.previousState?.timer;
 
+    // offset mode has been changed
+    const offsetModeChanged = RuntimeService.previousState?.runtime?.offsetMode !== state.runtime.offsetMode;
+
     // if playback changes most things should update
     const hasChangedPlayback = RuntimeService.previousState.timer?.playback !== state.timer.playback;
 
     // combine all big changes
-    const hasImmediateChanges = hasNewLoaded || justStarted || hasChangedPlayback;
+    const hasImmediateChanges = hasNewLoaded || justStarted || hasChangedPlayback || offsetModeChanged;
 
     /**
      * Timer should be updated if

apps/server/src/services/timerUtils.ts

@@ -156,6 +156,23 @@ export function getRuntimeOffset(state: RuntimeState): number {
   return startOffset - addedTime - pausedTime + overtime;
 }
 
+/**
+ * Calculates relative offset
+ * should always be calculated after the absolute offset
+ */
+export function getRelativeOffset(state: RuntimeState): number {
+  const { actualStart, plannedStart, offset } = state.runtime;
+  // eslint-disable-next-line no-unused-labels -- dev code path
+  DEV: {
+    // we know actualStart and plannedStart exists as long as a timer is running
+    if (actualStart === null || plannedStart === null) {
+      throw new Error('timerUtils.calculate: actualStart and plannedStart must be set');
+    }
+  }
+  const relativeStartOffset = actualStart - plannedStart;
+  return offset + relativeStartOffset;
+}
+
 /**
  * Calculates the expected end of the rundown
  */
@@ -164,7 +181,7 @@ export function getExpectedEnd(state: RuntimeState): MaybeNumber {
   if (state.runtime.actualStart === null || state.runtime.plannedEnd === null) {
     return null;
   }
-  return state.runtime.plannedEnd - state.runtime.offset + state._timer.totalDelay;
+  return state.runtime.plannedEnd - state.runtime.offset + state._rundown.totalDelay;
 }
 
 /**

apps/server/src/stores/__mocks__/runtimeState.mocks.ts

@@ -1,4 +1,4 @@
-import { TimerPhase, Playback } from 'ontime-types';
+import { TimerPhase, Playback, OffsetMode } from 'ontime-types';
 import { deepmerge } from 'ontime-utils';
 import type { RuntimeState } from '../runtimeState.js';
 
@@ -16,10 +16,12 @@ const baseState: RuntimeState = {
     selectedEventIndex: null,
     numEvents: 0,
     offset: 0,
+    relativeOffset: 0,
     plannedStart: 0,
     plannedEnd: 0,
     actualStart: null,
     expectedEnd: null,
+    offsetMode: OffsetMode.Absolute,
   },
   timer: {
     addedTime: 0,
@@ -35,10 +37,12 @@ const baseState: RuntimeState = {
   },
   _timer: {
     forceFinish: null,
-    totalDelay: 0,
     pausedAt: null,
     secondaryTarget: null,
   },
+  _rundown: {
+    totalDelay: 0,
+  },
 };
 
 export function makeRuntimeStateData(patch?: Partial<RuntimeState>): RuntimeState {

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

@@ -4,7 +4,7 @@ import { deepmerge } from 'ontime-utils';
 import {
   type RuntimeState,
   addTime,
-  clear,
+  hardClear,
   getState,
   load,
   loadBlock,
@@ -71,7 +71,7 @@ beforeAll(() => {
 
 describe('mutation on runtimeState', () => {
   beforeEach(() => {
-    clear();
+    hardClear();
 
     vi.mock('../../services/rundown-service/RundownService.js', async (importOriginal) => {
       const actual = (await importOriginal()) as object;
@@ -246,7 +246,7 @@ describe('roll mode', () => {
   beforeEach(() => {
     vi.useFakeTimers();
     vi.setSystemTime('jan 1 00:00');
-    clear();
+    hardClear();
   });
   afterEach(() => {
     vi.useRealTimers();

apps/server/src/stores/runtimeState.ts

@@ -3,6 +3,7 @@ import {
   isPlayableEvent,
   MaybeNumber,
   MaybeString,
+  OffsetMode,
   OntimeEvent,
   OntimeRundown,
   PlayableEvent,
@@ -27,6 +28,7 @@ import {
   getCurrent,
   getExpectedEnd,
   getExpectedFinish,
+  getRelativeOffset,
   getRuntimeOffset,
   getTimerPhase,
 } from '../services/timerUtils.js';
@@ -45,10 +47,12 @@ export type RuntimeState = {
   // private properties of the timer calculations
   _timer: {
     forceFinish: MaybeNumber; // whether we should declare an event as finished, will contain the finish time
-    totalDelay: number; // this value comes from rundown service
     pausedAt: MaybeNumber;
     secondaryTarget: MaybeNumber;
   };
+  _rundown: {
+    totalDelay: number; // this value comes from rundown service
+  };
 };
 
 const runtimeState: RuntimeState = {
@@ -62,10 +66,12 @@ const runtimeState: RuntimeState = {
   timer: { ...runtimeStorePlaceholder.timer },
   _timer: {
     forceFinish: null,
-    totalDelay: 0,
     pausedAt: null,
     secondaryTarget: null,
   },
+  _rundown: {
+    totalDelay: 0,
+  },
 };
 
 export function getState(): Readonly<RuntimeState> {
@@ -79,10 +85,36 @@ export function getState(): Readonly<RuntimeState> {
     runtime: { ...runtimeState.runtime },
     timer: { ...runtimeState.timer },
     _timer: { ...runtimeState._timer },
+    _rundown: { totalDelay: 0 },
   };
 }
 
-export function clear() {
+//TODO: find other things that dose not need clearing
+export function softClear() {
+  runtimeState.eventNow = null;
+  runtimeState.publicEventNow = null;
+  runtimeState.eventNext = null;
+  runtimeState.publicEventNext = null;
+
+  // runtimeState.currentBlock.block = null;
+  // runtimeState.currentBlock.startedAt = null;
+
+  runtimeState.runtime.offset = 0;
+  runtimeState.runtime.relativeOffset = 0;
+  runtimeState.runtime.expectedEnd = null;
+  runtimeState.runtime.selectedEventIndex = null;
+
+  runtimeState.timer.playback = Playback.Stop;
+  runtimeState.clock = clock.timeNow();
+  runtimeState.timer = { ...runtimeStorePlaceholder.timer };
+
+  // when clearing, we maintain the total delay from the rundown
+  runtimeState._timer.forceFinish = null;
+  runtimeState._timer.pausedAt = null;
+  runtimeState._timer.secondaryTarget = null;
+}
+
+export function hardClear() {
   runtimeState.eventNow = null;
   runtimeState.publicEventNow = null;
   runtimeState.eventNext = null;
@@ -93,6 +125,7 @@ export function clear() {
   runtimeState.publicEventNext = null;
 
   runtimeState.runtime.offset = 0;
+  runtimeState.runtime.relativeOffset = 0;
   runtimeState.runtime.actualStart = null;
   runtimeState.runtime.expectedEnd = null;
   runtimeState.runtime.selectedEventIndex = null;
@@ -137,7 +170,7 @@ type RundownData = {
  */
 export function updateRundownData(rundownData: RundownData) {
   // we keep this in private state since there is no UI use case for it
-  runtimeState._timer.totalDelay = rundownData.totalDelay;
+  runtimeState._rundown.totalDelay = rundownData.totalDelay;
 
   runtimeState.runtime.numEvents = rundownData.numEvents;
   runtimeState.runtime.plannedStart = rundownData.firstStart;
@@ -154,10 +187,7 @@ export function load(
   rundown: OntimeRundown,
   initialData?: Partial<TimerState & RestorePoint>,
 ): boolean {
-  // we need to persist the current block state across loads
-  const prevCurrentBlock = { ...runtimeState.currentBlock };
-  clear();
-  runtimeState.currentBlock = prevCurrentBlock;
+  softClear();
 
   // filter rundown
   const timedEvents = filterTimedEvents(rundown);
@@ -185,6 +215,7 @@ export function load(
     if (firstStart === null || typeof firstStart === 'number') {
       runtimeState.runtime.actualStart = firstStart;
       runtimeState.runtime.offset = getRuntimeOffset(runtimeState);
+      runtimeState.runtime.relativeOffset = getRelativeOffset(runtimeState);
       runtimeState.runtime.expectedEnd = getExpectedEnd(runtimeState);
     }
     if (typeof initialData.blockStartAt === 'number') {
@@ -390,6 +421,7 @@ export function start(state: RuntimeState = runtimeState): boolean {
 
   // update offset
   state.runtime.offset = getRuntimeOffset(state);
+  state.runtime.relativeOffset = getRelativeOffset(state);
   state.runtime.expectedEnd = state.runtime.plannedEnd - state.runtime.offset;
   return true;
 }
@@ -409,9 +441,7 @@ export function stop(state: RuntimeState = runtimeState): boolean {
   if (state.timer.playback === Playback.Stop) {
     return false;
   }
-  clear();
-  runtimeState.runtime.actualStart = null;
-  runtimeState.runtime.expectedEnd = null;
+  hardClear();
   return true;
 }
 
@@ -453,6 +483,7 @@ export function addTime(amount: number) {
 
   // update runtime delays: over - under
   runtimeState.runtime.offset = getRuntimeOffset(runtimeState);
+  runtimeState.runtime.relativeOffset = getRelativeOffset(runtimeState);
   runtimeState.runtime.expectedEnd = getExpectedEnd(runtimeState);
 
   return true;
@@ -498,6 +529,7 @@ export function update(): UpdateResult {
 
   // update runtime, needs up-to-date timer state
   runtimeState.runtime.offset = getRuntimeOffset(runtimeState);
+  runtimeState.runtime.relativeOffset = getRelativeOffset(runtimeState);
   runtimeState.runtime.expectedEnd = getExpectedEnd(runtimeState);
 
   const finishedNow =
@@ -604,9 +636,7 @@ export function roll(rundown: OntimeRundown, offset = 0): { eventId: MaybeString
   }
 
   // we need to persist the current block state across loads
-  const prevCurrentBlock = { ...runtimeState.currentBlock };
-  clear();
-  runtimeState.currentBlock = prevCurrentBlock;
+  softClear();
 
   //account for offset but we only keep it if passed to us
   runtimeState.runtime.offset = offset;
@@ -696,3 +726,7 @@ export function loadBlock(rundown: OntimeRundown, state = runtimeState) {
   // update the block anyway
   state.currentBlock.block = newCurrentBlock === null ? null : { ...newCurrentBlock };
 }
+
+export function setOffsetMode(mode: OffsetMode) {
+  runtimeState.runtime.offsetMode = mode;
+}

e2e/tests/features/212-time-until.spec.ts

@@ -1,6 +1,6 @@
 import { expect, test } from '@playwright/test';
 
-test('linked time until', async ({ page }) => {
+test('time until absolute', async ({ page }) => {
   await page.goto('http://localhost:4001/editor');
 
   await page.getByRole('button', { name: 'Clear rundown' }).click();
@@ -11,7 +11,46 @@ test('linked time until', async ({ page }) => {
   await page.getByRole('button', { name: 'Event', exact: true }).nth(1).click();
   await page.getByRole('button', { name: 'Event', exact: true }).nth(1).click();
 
+  await page.getByRole('button', { name: 'Absolute' }).click();
   await page.getByTestId('entry-1').getByLabel('Start event').click();
+  await expect(page.getByTestId('offset')).not.toContainText('00:00:00'); // This might be a bad test requires that the test is not run at 0h
+  await page.getByLabel('Pause event').click();
+
+  await expect(page.getByTestId('entry-2').locator('#event-block')).toContainText('9m');
+  await expect(page.getByTestId('entry-3').locator('#event-block')).toContainText('19m');
+  await expect(page.getByTestId('entry-4').locator('#event-block')).toContainText('29m');
+
+  await page.getByTestId('entry-1').getByTestId('time-input-duration').click();
+  await page.getByTestId('entry-1').getByTestId('time-input-duration').fill('6h');
+  await page.getByTestId('entry-1').getByTestId('time-input-duration').press('Enter');
+
+  await expect(page.getByTestId('entry-2').locator('#event-block')).toContainText('5h59m');
+  await expect(page.getByTestId('entry-3').locator('#event-block')).toContainText('6h9m');
+  await expect(page.getByTestId('entry-4').locator('#event-block')).toContainText('6h19m');
+
+  await page.getByTestId('entry-1').getByTestId('time-input-duration').click();
+  await page.getByTestId('entry-1').getByTestId('time-input-duration').fill('30s');
+  await page.getByTestId('entry-1').getByTestId('time-input-duration').press('Enter');
+
+  await expect(page.getByTestId('entry-2').locator('#event-block')).toContainText('29s');
+  await expect(page.getByTestId('entry-3').locator('#event-block')).toContainText('10m');
+  await expect(page.getByTestId('entry-4').locator('#event-block')).toContainText('20m');
+});
+
+test('time until relative', async ({ page }) => {
+  await page.goto('http://localhost:4001/editor');
+
+  await page.getByRole('button', { name: 'Clear rundown' }).click();
+  await page.getByRole('button', { name: 'Delete all' }).click();
+
+  await page.getByRole('button', { name: 'Create Event' }).click();
+  await page.getByRole('button', { name: 'Event' }).nth(4).click();
+  await page.getByRole('button', { name: 'Event', exact: true }).nth(1).click();
+  await page.getByRole('button', { name: 'Event', exact: true }).nth(1).click();
+
+  await page.getByRole('button', { name: 'Relative' }).click();
+  await page.getByTestId('entry-1').getByLabel('Start event').click();
+  await expect(page.getByTestId('offset')).toContainText('00:00:00'); // This might be a bad test as it ruires the evaluation to happen within 1s
   await page.getByLabel('Pause event').click();
 
   await expect(page.getByTestId('entry-2').locator('#event-block')).toContainText('9m');

packages/types/src/definitions/runtime/Runtime.type.ts

@@ -1,11 +1,18 @@
 import type { MaybeNumber } from '../../utils/utils.type.js';
 
+export enum OffsetMode {
+  Absolute = 'absolute',
+  Relative = 'relative',
+}
+
 export type Runtime = {
   numEvents: number;
   selectedEventIndex: MaybeNumber;
   offset: number;
+  relativeOffset: number;
   plannedStart: MaybeNumber;
   actualStart: MaybeNumber;
   plannedEnd: MaybeNumber;
   expectedEnd: MaybeNumber;
+  offsetMode: OffsetMode;
 };

packages/types/src/definitions/runtime/RuntimeStore.ts

@@ -1,9 +1,10 @@
 import { SimpleDirection, SimplePlayback } from './AuxTimer.type.js';
 import { Playback } from './Playback.type.js';
+import { OffsetMode } from './Runtime.type.js';
 import type { RuntimeStore } from './RuntimeStore.type.js';
 import { TimerPhase } from './TimerState.type.js';
 
-export const runtimeStorePlaceholder: RuntimeStore = {
+export const runtimeStorePlaceholder: Readonly<RuntimeStore> = {
   clock: 0,
   timer: {
     addedTime: 0,
@@ -32,10 +33,12 @@ export const runtimeStorePlaceholder: RuntimeStore = {
     selectedEventIndex: null, // changes if rundown changes or we load a new event
     numEvents: 0, // change initiated by user
     offset: 0, // changes at runtime
+    relativeOffset: 0, // changes at runtime
     plannedStart: 0, // only changes if event changes
     plannedEnd: 0, // only changes if event changes, overflows over dayInMs
     actualStart: null, // set once we start the timer
     expectedEnd: null, // changes with runtime, based on offset, overflows over dayInMs
+    offsetMode: OffsetMode.Absolute,
   },
   currentBlock: {
     block: null,

packages/types/src/index.ts

@@ -87,6 +87,7 @@ export { TimerLifeCycle, timerLifecycleValues } from './definitions/core/TimerLi
 export type { TimerMessage, MessageState, SecondarySource } from './definitions/runtime/MessageControl.type.js';
 
 export type { Runtime } from './definitions/runtime/Runtime.type.js';
+export { OffsetMode } from './definitions/runtime/Runtime.type.js';
 export type { RuntimeStore } from './definitions/runtime/RuntimeStore.type.js';
 export { runtimeStorePlaceholder } from './definitions/runtime/RuntimeStore.js';
 export { type TimerState, TimerPhase } from './definitions/runtime/TimerState.type.js';