diff --git a/apps/client/src/common/api/rundown.ts b/apps/client/src/common/api/rundown.ts
index 66965eb20..46932257c 100644
--- a/apps/client/src/common/api/rundown.ts
+++ b/apps/client/src/common/api/rundown.ts
@@ -176,6 +176,13 @@ export async function postCloneEntry(
   return axios.post(`${rundownPath}/${rundownId}/clone/${entryId}`, options);
 }
 
+/**
+ * HTTP request events duration to fit inside the group target
+ */
+export async function requestFitGroupTarget(rundownId: RundownId, eventId: EntryId): Promise<AxiosResponse<Rundown>> {
+  return axios.post(`${rundownPath}/${rundownId}/${eventId}/fit-group-duration`);
+}
+
 /**
  * HTTP request for grouping a list of entries into a group
  */
diff --git a/apps/client/src/common/hooks/useEntryAction.ts b/apps/client/src/common/hooks/useEntryAction.ts
index 9386c66a4..a561e416e 100644
--- a/apps/client/src/common/hooks/useEntryAction.ts
+++ b/apps/client/src/common/hooks/useEntryAction.ts
@@ -49,6 +49,7 @@ import {
   requestEventSwap,
   requestGroupEntries,
   requestUngroup,
+  requestFitGroupTarget,
 } from '../api/rundown';
 import { logAxiosError } from '../api/utils';
 import { useEditorSettings } from '../stores/editorSettings';
@@ -466,7 +467,27 @@ function useEntryActionsForRundown(scopedRundownId: string | undefined) {
         return previousEnd;
       }
     },
-    [getCurrentRundownData, updateEntryMutation, queryClient],
+    [getCurrentRundownData, updateEntryMutation, queryClient, resolveCurrentRundownQueryKey],
+  );
+
+  /**
+   * Updates time of existing event so it satisfies the group target duration
+   * @param eventId {EntryId} - id of the event
+   */
+  const matchGroupDuration = useCallback(
+    async (eventId: EntryId) => {
+      const rundownId = getCurrentRundownData()?.id;
+      if (!rundownId) {
+        throw new Error('Rundown not initialised');
+      }
+
+      try {
+        await requestFitGroupTarget(rundownId, eventId);
+      } catch (error) {
+        logAxiosError('Error updating event', error);
+      }
+    },
+    [getCurrentRundownData],
   );
 
   /**
@@ -1009,6 +1030,7 @@ function useEntryActionsForRundown(scopedRundownId: string | undefined) {
       swapEvents,
       updateEntry,
       updateTimer,
+      matchGroupDuration,
     }),
     [
       addEntry,
@@ -1026,6 +1048,7 @@ function useEntryActionsForRundown(scopedRundownId: string | undefined) {
       swapEvents,
       updateEntry,
       updateTimer,
+      matchGroupDuration,
     ],
   );
 }
diff --git a/apps/client/src/features/rundown/entry-editor/GroupEditor.tsx b/apps/client/src/features/rundown/entry-editor/GroupEditor.tsx
index f1508cd93..94b4e831e 100644
--- a/apps/client/src/features/rundown/entry-editor/GroupEditor.tsx
+++ b/apps/client/src/features/rundown/entry-editor/GroupEditor.tsx
@@ -81,7 +81,7 @@ export default function GroupEditor({ group }: GroupEditorProps) {
           <div>
             <Editor.Label htmlFor='eventId'>Plan offset</Editor.Label>
             <TextLikeInput
-              offset={planOffsetLabel}
+              offset={planOffsetLabel === 'under' ? 'over' : planOffsetLabel}
               className={cx([style.textLikeInput, planOffset === null && style.inactive])}
               disabled
             >
diff --git a/apps/client/src/features/rundown/rundown-event/RundownEvent.tsx b/apps/client/src/features/rundown/rundown-event/RundownEvent.tsx
index aea2c4ef2..2c0428e92 100644
--- a/apps/client/src/features/rundown/rundown-event/RundownEvent.tsx
+++ b/apps/client/src/features/rundown/rundown-event/RundownEvent.tsx
@@ -1,6 +1,6 @@
 import { useSortable } from '@dnd-kit/sortable';
 import { CSS } from '@dnd-kit/utilities';
-import { Day, EndAction, EntryId, Playback, TimeStrategy, TimerType } from 'ontime-types';
+import { Day, EndAction, EntryId, Maybe, OntimeGroup, Playback, TimeStrategy, TimerType } from 'ontime-types';
 import { isPlaybackActive } from 'ontime-utils';
 import { MouseEvent, useEffect, useRef } from 'react';
 import {
@@ -13,9 +13,10 @@ import {
   IoTrash,
   IoUnlink,
 } from 'react-icons/io5';
-import { TbFlagFilled, TbListNumbers } from 'react-icons/tb';
+import { TbClockPin, TbFlagFilled, TbListNumbers } from 'react-icons/tb';
 
 import { useEntryActionsContext } from '../../../common/context/EntryActionsContext';
+import { useEntry } from '../../../common/hooks-query/useRundown';
 import { useContextMenu } from '../../../common/hooks/useContextMenu';
 import { useEntryCopy } from '../../../common/stores/entryCopyStore';
 import { deviceAlt, deviceMod } from '../../../common/utils/deviceUtils';
@@ -102,7 +103,10 @@ export default function RundownEvent({
   const clearSelectedEventId = useEventIdSwapping((state) => state.clearSelectedEventId);
   const openRenumberDialog = useRenumberCuesDialogStore((state) => state.onOpen);
 
-  const { updateEntry, batchUpdateEvents, clone, deleteEntry, groupEntries, swapEvents } = useEntryActionsContext();
+  const parentGroup = useEntry(parent) as Maybe<OntimeGroup>;
+
+  const { updateEntry, batchUpdateEvents, clone, deleteEntry, groupEntries, swapEvents, matchGroupDuration } =
+    useEntryActionsContext();
 
   const isSelected = useEventSelection((state) => state.selectedEvents.has(eventId));
   const unselect = useEventSelection((state) => state.unselect);
@@ -114,6 +118,15 @@ export default function RundownEvent({
 
   const handleRef = useRef<null | HTMLSpanElement>(null);
 
+  const [enableMatchDuration, groupTargetDurationDescription] = (() => {
+    if (!parentGroup || parentGroup.targetDuration === null || parentGroup.duration === parentGroup.targetDuration)
+      return [false, ''];
+    const { targetDuration, duration } = parentGroup;
+    return targetDuration > duration
+      ? [true, 'Increase event duration to fit the group target']
+      : [true, 'Decrease event duration to fit the group target'];
+  })();
+
   const [onContextMenu] = useContextMenu<HTMLDivElement>(() =>
     selectedEvents.size > 1
       ? [
@@ -172,6 +185,17 @@ export default function RundownEvent({
               updateEntry({ id: eventId, flag: !flag });
             },
           },
+          {
+            type: 'item',
+            label: 'Match Group Target Duration',
+            description: groupTargetDurationDescription,
+            icon: TbClockPin,
+            onClick: () => {
+              if (!parent) return;
+              matchGroupDuration(eventId);
+            },
+            disabled: !enableMatchDuration,
+          },
           { type: 'divider' },
           {
             type: 'item',
diff --git a/apps/client/src/features/rundown/rundown-group/RundownGroup.module.scss b/apps/client/src/features/rundown/rundown-group/RundownGroup.module.scss
index ad3e094cf..d26124860 100644
--- a/apps/client/src/features/rundown/rundown-group/RundownGroup.module.scss
+++ b/apps/client/src/features/rundown/rundown-group/RundownGroup.module.scss
@@ -74,42 +74,36 @@
   .metaLabel {
     color: $muted-gray;
     font-size: calc(1rem - 3px);
+    display: flex;
+    align-items: center;
+    gap: 0.25rem;
   }
 }
 
-.strike {
-  text-decoration: wavy underline;
-  margin-right: 0.25rem;
-  color: $ui-white;
-}
-
 .duration {
   display: flex;
   align-items: center;
   gap: 0.25rem;
+  color: $ui-white;
+
+  &.warning {
+    .strike {
+      // color: $playback-over;
+      text-decoration: wavy underline;
+      text-decoration-color: $playback-over;
+    }
+    .offsetLabel {
+      background-color: $playback-over;
+    }
+  }
 }
 
 .lockIcon {
-  opacity: 0.6;
+  color: $muted-gray;
 }
 
-.over {
-  color: $playback-over;
-  .strike {
-    text-decoration-color: $playback-over;
-  }
-  .offsetLabel {
-    background-color: $playback-over;
-  }
-}
-.under {
-  color: $playback-under;
-  .strike {
-    text-decoration-color: $playback-under;
-  }
-  .offsetLabel {
-    background-color: $playback-under;
-  }
+.target {
+  display: contents;
 }
 
 .drag {
diff --git a/apps/client/src/features/rundown/rundown-group/RundownGroup.tsx b/apps/client/src/features/rundown/rundown-group/RundownGroup.tsx
index 69cc3f0ce..91a8ca56d 100644
--- a/apps/client/src/features/rundown/rundown-group/RundownGroup.tsx
+++ b/apps/client/src/features/rundown/rundown-group/RundownGroup.tsx
@@ -2,24 +2,25 @@ import { useSortable } from '@dnd-kit/sortable';
 import { CSS } from '@dnd-kit/utilities';
 import { EntryId, OntimeGroup } from 'ontime-types';
 import { MILLIS_PER_MINUTE } from 'ontime-utils';
-import { MouseEvent, useRef } from 'react';
+import { MouseEvent, useCallback, useRef } from 'react';
 import {
   IoChevronDown,
   IoChevronUp,
   IoDuplicateOutline,
   IoFolderOpenOutline,
-  IoLockClosed,
   IoReorderTwo,
   IoTrash,
+  IoLockClosed,
 } from 'react-icons/io5';
+import { TbClockPin } from 'react-icons/tb';
 
 import IconButton from '../../../common/components/buttons/IconButton';
 import Tag from '../../../common/components/tag/Tag';
+import Tooltip from '../../../common/components/tooltip/Tooltip';
 import { useEntryActionsContext } from '../../../common/context/EntryActionsContext';
 import { useContextMenu } from '../../../common/hooks/useContextMenu';
 import { useEntryCopy } from '../../../common/stores/entryCopyStore';
 import { deviceAlt, deviceMod } from '../../../common/utils/deviceUtils';
-import { getOffsetState } from '../../../common/utils/offset';
 import { cx, getAccessibleColour } from '../../../common/utils/styleUtils';
 import { formatDuration, formatTime } from '../../../common/utils/time';
 import TitleEditor from '../common/TitleEditor';
@@ -40,12 +41,31 @@ export default function RundownGroup({ data, hasCursor, collapsed, onCollapse }:
   'use memo';
 
   const handleRef = useRef<null | HTMLSpanElement>(null);
-  const { clone, ungroup, deleteEntry } = useEntryActionsContext();
+  const { clone, ungroup, deleteEntry, updateEntry } = useEntryActionsContext();
 
   const selectSingleEntry = useEventSelection((state) => state.setSingleEntrySelection);
   const selectedEvents = useEventSelection((state) => state.selectedEvents);
   const entryCopyId = useEntryCopy((state) => state.entryCopyId);
 
+  const isDurationMatching = data.targetDuration !== null && data.targetDuration === data.duration;
+
+  const [planOffset, offset] = (() => {
+    if (data.targetDuration === null) {
+      return [null, 0];
+    }
+
+    const offset = data.duration - data.targetDuration;
+    if (offset === 0) {
+      return [null, 0];
+    }
+    const absOffset = Math.abs(offset);
+    return [`${offset < 0 ? '-' : '+'}${formatDuration(absOffset, absOffset > 2 * MILLIS_PER_MINUTE)}`, offset];
+  })();
+
+  const matchDuration = useCallback(() => {
+    updateEntry({ id: data.id, targetDuration: data.duration });
+  }, [data.duration, data.id, updateEntry]);
+
   const [onContextMenu] = useContextMenu<HTMLDivElement>(() => [
     {
       type: 'item',
@@ -62,6 +82,18 @@ export default function RundownGroup({ data, hasCursor, collapsed, onCollapse }:
       disabled: data.entries.length === 0,
     },
     { type: 'divider' },
+    {
+      type: 'item',
+      label: 'Match Content Duration',
+      icon: TbClockPin,
+      onClick: matchDuration,
+      disabled: isDurationMatching,
+      description:
+        offset > 0
+          ? "Increase group target duration to match it's contents"
+          : "Decrease group target duration to match it's contents",
+    },
+    { type: 'divider' },
     {
       type: 'item',
       label: 'Delete Group',
@@ -105,22 +137,6 @@ export default function RundownGroup({ data, hasCursor, collapsed, onCollapse }:
   const binderColours = data.colour && getAccessibleColour(data.colour);
   const isValidDrop = isDragging && over?.id && canDrop(over.data.current?.type, over.data.current?.parent);
 
-  const [planOffset, planOffsetLabel] = (() => {
-    if (data.targetDuration === null) {
-      return [null, null];
-    }
-
-    const offset = data.duration - data.targetDuration;
-    if (offset === 0) {
-      return [null, 'under'];
-    }
-    const absOffset = Math.abs(offset);
-    return [
-      `${offset < 0 ? '-' : '+'}${formatDuration(absOffset, absOffset > 2 * MILLIS_PER_MINUTE)}`,
-      getOffsetState(offset),
-    ];
-  })();
-
   const dragStyle = {
     zIndex: isDragging ? 2 : 'inherit',
     transform: CSS.Translate.toString(transform),
@@ -175,20 +191,18 @@ export default function RundownGroup({ data, hasCursor, collapsed, onCollapse }:
             <div className={style.metaLabel}>End</div>
             <div>{formatTime(data.timeEnd)}</div>
           </div>
-          <div className={style.metaEntry}>
-            <div className={style.metaLabel}>Duration</div>
-            <div className={style.duration}>
-              {planOffset === null ? (
-                formatDuration(data.duration)
-              ) : (
-                <span className={cx([planOffsetLabel && style[planOffsetLabel]])}>
-                  <span className={style.strike}>{formatDuration(data.duration)}</span>
-                  <Tag className={style.offsetLabel}>{planOffset}</Tag>
-                </span>
-              )}
-              {data.targetDuration !== null && <IoLockClosed className={style.lockIcon} />}
+          <Tooltip text={'Group has target duration'} disabled={data.targetDuration === null}>
+            <div className={style.metaEntry}>
+              <div className={style.metaLabel}>
+                Duration
+                {data.targetDuration !== null && <IoLockClosed className={style.lockIcon} />}
+              </div>
+              <div className={cx([style.duration, planOffset && style.warning])}>
+                <span className={style.strike}>{formatDuration(data.duration)}</span>
+                {planOffset && <Tag className={style.offsetLabel}>{planOffset}</Tag>}
+              </div>
             </div>
-          </div>
+          </Tooltip>
         </div>
       </div>
     </div>
diff --git a/apps/server/src/api-data/rundown/__tests__/rundown.utils.test.ts b/apps/server/src/api-data/rundown/__tests__/rundown.utils.test.ts
index faae100e0..0e5d9b349 100644
--- a/apps/server/src/api-data/rundown/__tests__/rundown.utils.test.ts
+++ b/apps/server/src/api-data/rundown/__tests__/rundown.utils.test.ts
@@ -8,7 +8,7 @@ import {
   TimerType,
   Trigger,
 } from 'ontime-types';
-import { MILLIS_PER_HOUR, createEvent } from 'ontime-utils';
+import { MILLIS_PER_HOUR, MILLIS_PER_MINUTE, createEvent } from 'ontime-utils';
 import { assertType } from 'vitest';
 
 import { makeOntimeEvent, makeOntimeGroup, makeOntimeMilestone, makeRundown } from '../__mocks__/rundown.mocks.js';
@@ -22,6 +22,7 @@ import {
   makeDeepClone,
   mergeRundownPreservingFields,
   isLoadedPlayable,
+  eventDurationMatchGroupTarget,
 } from '../rundown.utils.js';
 
 describe('test event validator', () => {
@@ -610,3 +611,107 @@ describe('isLoadedPlayable()', () => {
     expect(isLoadedPlayable('keynote', rundown)).toBe(false);
   });
 });
+
+describe('eventDurationMatchGroupTarget()', () => {
+  it('returns unchanged duration when group already matches target', () => {
+    const result = eventDurationMatchGroupTarget({
+      targetDuration: MILLIS_PER_HOUR,
+      groupDuration: MILLIS_PER_HOUR,
+      eventDuration: MILLIS_PER_MINUTE * 30,
+    });
+    expect(result).toStrictEqual(null);
+  });
+
+  it('increases event duration when group is shorter than target', () => {
+    // Group is 1h short of target, so event duration increases by 1h
+    const result = eventDurationMatchGroupTarget({
+      targetDuration: MILLIS_PER_HOUR * 2, // 2h
+      groupDuration: MILLIS_PER_HOUR, // 1h
+      eventDuration: MILLIS_PER_MINUTE * 30, // 30m
+    });
+    expect(result).toStrictEqual(MILLIS_PER_HOUR + MILLIS_PER_MINUTE * 30); // 1h30m
+  });
+
+  it('decreases event duration when group is longer than target', () => {
+    // Group is 30m over target, so event duration decreases by 30m
+    const result = eventDurationMatchGroupTarget({
+      targetDuration: MILLIS_PER_HOUR, // 1h
+      groupDuration: MILLIS_PER_HOUR + MILLIS_PER_MINUTE * 30, // 1h30m
+      eventDuration: MILLIS_PER_MINUTE * 30, // 30m
+    });
+    expect(result).toStrictEqual(0);
+  });
+
+  it('handles zero target duration', () => {
+    const result = eventDurationMatchGroupTarget({
+      targetDuration: 0,
+      groupDuration: MILLIS_PER_HOUR,
+      eventDuration: MILLIS_PER_HOUR,
+    });
+    expect(result).toStrictEqual(0);
+  });
+
+  it('handles zero group duration', () => {
+    const result = eventDurationMatchGroupTarget({
+      targetDuration: MILLIS_PER_HOUR,
+      groupDuration: 0,
+      eventDuration: MILLIS_PER_MINUTE * 30,
+    });
+    expect(result).toStrictEqual(MILLIS_PER_HOUR + MILLIS_PER_MINUTE * 30);
+  });
+
+  it('handles zero event duration', () => {
+    const result = eventDurationMatchGroupTarget({
+      targetDuration: MILLIS_PER_HOUR,
+      groupDuration: MILLIS_PER_MINUTE * 30,
+      eventDuration: 0,
+    });
+    expect(result).toStrictEqual(MILLIS_PER_HOUR - MILLIS_PER_MINUTE * 30);
+  });
+
+  it('handles all zero values', () => {
+    const result = eventDurationMatchGroupTarget({
+      targetDuration: 0,
+      groupDuration: 0,
+      eventDuration: 0,
+    });
+    expect(result).toStrictEqual(null);
+  });
+
+  it('returns null when result would be negative', () => {
+    // Group exceeds target by 1.5h, event shrinks by 1.5h (exceeds event duration)
+    const result = eventDurationMatchGroupTarget({
+      targetDuration: MILLIS_PER_MINUTE * 30,
+      groupDuration: MILLIS_PER_HOUR * 2,
+      eventDuration: MILLIS_PER_HOUR,
+    });
+    expect(result).toStrictEqual(null);
+  });
+
+  it('handles large durations', () => {
+    const result = eventDurationMatchGroupTarget({
+      targetDuration: MILLIS_PER_HOUR * 24, // 24h
+      groupDuration: MILLIS_PER_HOUR * 12, // 12h
+      eventDuration: MILLIS_PER_HOUR, // 1h
+    });
+    expect(result).toStrictEqual(MILLIS_PER_HOUR * 13); // 13h
+  });
+
+  it('returns null when targetDuration is null', () => {
+    const result = eventDurationMatchGroupTarget({
+      targetDuration: null,
+      groupDuration: MILLIS_PER_HOUR,
+      eventDuration: MILLIS_PER_MINUTE * 30,
+    });
+    expect(result).toStrictEqual(null);
+  });
+
+  it('returns null when duration would be over 24h', () => {
+    const result = eventDurationMatchGroupTarget({
+      targetDuration: 30 * MILLIS_PER_HOUR,
+      groupDuration: MILLIS_PER_HOUR,
+      eventDuration: MILLIS_PER_MINUTE * 30,
+    });
+    expect(result).toStrictEqual(null);
+  });
+});
diff --git a/apps/server/src/api-data/rundown/rundown.router.ts b/apps/server/src/api-data/rundown/rundown.router.ts
index 69848db76..34ba229f3 100644
--- a/apps/server/src/api-data/rundown/rundown.router.ts
+++ b/apps/server/src/api-data/rundown/rundown.router.ts
@@ -35,6 +35,7 @@ import {
   reorderEntry,
   swapEvents,
   ungroupEntries,
+  entryFitGroupDuration,
 } from './rundown.service.js';
 import { normalisedToRundownArray } from './rundown.utils.js';
 import {
@@ -337,6 +338,23 @@ router.post('/:rundownId/ungroup/:id', paramsWithId, async (req: Request, res: R
   }
 });
 
+/**
+ * Change a events duration to fit inside the group target
+ */
+router.post(
+  '/:rundownId/:id/fit-group-duration',
+  paramsWithId,
+  async (req: Request, res: Response<Rundown | ErrorResponse>) => {
+    try {
+      const rundown = await entryFitGroupDuration(req.params.rundownId, req.params.id);
+      res.status(200).send(rundown);
+    } catch (error) {
+      const message = getErrorMessage(error);
+      res.status(400).send({ message });
+    }
+  },
+);
+
 /**
  * Deletes a list of entries by their ID
  */
diff --git a/apps/server/src/api-data/rundown/rundown.service.ts b/apps/server/src/api-data/rundown/rundown.service.ts
index 44c2f1637..b4ceb8f16 100644
--- a/apps/server/src/api-data/rundown/rundown.service.ts
+++ b/apps/server/src/api-data/rundown/rundown.service.ts
@@ -47,6 +47,7 @@ import {
   hasChanges,
   mergeRundownPreservingFields,
   isLoadedPlayable,
+  eventDurationMatchGroupTarget,
 } from './rundown.utils.js';
 import { assertInsertAnchorExists, assertInsertAnchorInOrder, assertSingleInsertAnchor } from './rundown.validation.js';
 
@@ -447,6 +448,69 @@ export async function cloneEntry(rundownId: string, entryId: EntryId, options: I
   return rundownResult;
 }
 
+/**
+ *  Change a events duration to fit inside the group target
+ */
+export async function entryFitGroupDuration(rundownId: string, entryId: EntryId): Promise<Rundown> {
+  const { rundown, commit } = createTransaction({ rundownId, mutableRundown: true });
+
+  const entry = rundown.entries[entryId];
+
+  if (!entry) {
+    throw new Error('Entry not found');
+  }
+
+  if (!isOntimeEvent(entry)) {
+    throw new Error('Entry must be an event');
+  }
+
+  const { parent } = entry;
+  if (!parent) {
+    throw new Error('Entry must be in a group');
+  }
+
+  const group = rundown.entries[parent];
+
+  if (!group) {
+    throw new Error('Group not found');
+  }
+
+  if (!isOntimeGroup(group)) {
+    throw new Error('Group is not a group');
+  }
+
+  const newDuration = eventDurationMatchGroupTarget({
+    targetDuration: group.targetDuration,
+    groupDuration: group.duration,
+    eventDuration: entry.duration,
+  });
+
+  if (newDuration === null) {
+    throw new Error('Unable to fit a duration');
+  }
+
+  const newEnd = entry.timeStart + newDuration;
+
+  rundownMutation.edit(rundown, {
+    id: entryId,
+    duration: newDuration,
+    timeEnd: newEnd,
+    timeStrategy: entry.timeStrategy,
+  });
+  const { rundown: rundownResult, rundownMetadata, revision } = await commit();
+
+  // schedule the side effects
+  setImmediate(() => {
+    // notify runtime that rundown has changed
+    updateRuntimeOnChange(rundownMetadata);
+
+    // we need to notify the timer since we might be changing a running event
+    notifyChanges(rundown.id, rundownMetadata, revision, { external: true, timer: true });
+  });
+
+  return rundownResult;
+}
+
 /**
  * Groups a list of entries into a new group
  */
diff --git a/apps/server/src/api-data/rundown/rundown.utils.ts b/apps/server/src/api-data/rundown/rundown.utils.ts
index 01b256cd7..f1d9e1be9 100644
--- a/apps/server/src/api-data/rundown/rundown.utils.ts
+++ b/apps/server/src/api-data/rundown/rundown.utils.ts
@@ -3,6 +3,7 @@ import {
   EntryCustomFields,
   EntryId,
   ImportedFields,
+  Maybe,
   OntimeBaseEvent,
   OntimeDelay,
   OntimeEntry,
@@ -30,6 +31,7 @@ import {
   generateId,
   getCueCandidate,
   makeString,
+  maxDuration,
   validateEndAction,
   validateTimerType,
   validateTimes,
@@ -601,3 +603,27 @@ export function getIntegerAndFraction(value: string): IncrementNumber {
     precision,
   };
 }
+
+/**
+ * Adjusts an event's duration to fit inside the group target
+ * @param targetDuration - The desired total duration for the group, or null
+ * @param groupDuration - The current total duration of all events in the group
+ * @param eventDuration - The current duration of the event being adjusted
+ * @returns The adjusted event duration, or null if targetDuration is null or
+ *          the result would be negative
+ */
+export function eventDurationMatchGroupTarget({
+  targetDuration,
+  groupDuration,
+  eventDuration,
+}: {
+  targetDuration: Maybe<number>;
+  groupDuration: number;
+  eventDuration: number;
+}): Maybe<number> {
+  if (targetDuration === null) return null;
+  if (targetDuration === groupDuration) return null;
+  const durationDiff = targetDuration - groupDuration;
+  const newDuration = eventDuration + durationDiff;
+  return newDuration < 0 || newDuration > maxDuration ? null : newDuration;
+}