diff --git a/packages/web/src/views/Week/components/Draft/hooks/actions/draft-resize.util.test.ts b/packages/web/src/views/Week/components/Draft/hooks/actions/draft-resize.util.test.ts
new file mode 100644
index 000000000..470d5114b
--- /dev/null
+++ b/packages/web/src/views/Week/components/Draft/hooks/actions/draft-resize.util.test.ts
@@ -0,0 +1,117 @@
+import dayjs from "@core/util/date/dayjs";
+import { type GridEventDraft } from "@web/events/event-draft.types";
+import { resizeDraft } from "./draft-resize.util";
+import { describe, expect, it } from "bun:test";
+
+const timedDraft = (
+  start = "2024-01-15T10:00:00.000Z",
+  end = "2024-01-15T11:00:00.000Z",
+): GridEventDraft =>
+  ({
+    kind: "create",
+    values: {
+      schedule: {
+        kind: "timed",
+        start: new Date(start),
+        end: new Date(end),
+        timeZone: "UTC",
+      },
+    },
+  }) as GridEventDraft;
+
+const allDayDraft = (): GridEventDraft =>
+  ({
+    kind: "create",
+    values: {
+      schedule: {
+        kind: "allDay",
+        start: new Date("2024-01-15T00:00:00.000Z"),
+        end: new Date("2024-01-16T00:00:00.000Z"),
+      },
+    },
+  }) as GridEventDraft;
+
+describe("resizeDraft", () => {
+  it("updates a timed end edge without changing the active edge", () => {
+    const draft = timedDraft();
+    const result = resizeDraft({
+      currTime: dayjs("2024-01-15T12:00:00.000Z"),
+      dateBeingChanged: "endDate",
+      draft,
+      origin: draft,
+    });
+
+    expect(result?.flippedTo).toBeNull();
+    expect(result?.hasMoved).toBe(true);
+    expect(dayjs(result?.draft.values.schedule.end).toISOString()).toBe(
+      "2024-01-15T12:00:00.000Z",
+    );
+  });
+
+  it("flips a start-edge resize once it crosses the end", () => {
+    const draft = timedDraft();
+    const result = resizeDraft({
+      currTime: dayjs("2024-01-15T12:00:00.000Z"),
+      dateBeingChanged: "startDate",
+      draft,
+      origin: draft,
+    });
+
+    expect(result?.flippedTo).toBe("endDate");
+    expect(dayjs(result?.draft.values.schedule.start).toISOString()).toBe(
+      "2024-01-15T11:00:00.000Z",
+    );
+    expect(dayjs(result?.draft.values.schedule.end).toISOString()).toBe(
+      "2024-01-15T12:00:00.000Z",
+    );
+    expect(result?.hasMoved).toBe(true);
+  });
+
+  it("flips an end-edge resize once it crosses the start", () => {
+    const draft = timedDraft();
+    const result = resizeDraft({
+      currTime: dayjs("2024-01-15T09:00:00.000Z"),
+      dateBeingChanged: "endDate",
+      draft,
+      origin: draft,
+    });
+
+    expect(result?.flippedTo).toBe("startDate");
+    expect(dayjs(result?.draft.values.schedule.start).toISOString()).toBe(
+      "2024-01-15T09:00:00.000Z",
+    );
+    expect(dayjs(result?.draft.values.schedule.end).toISOString()).toBe(
+      "2024-01-15T10:00:00.000Z",
+    );
+    expect(result?.hasMoved).toBe(true);
+  });
+
+  it("resizes all-day events by calendar day", () => {
+    const draft = allDayDraft();
+    const result = resizeDraft({
+      currTime: dayjs("2024-01-17T00:00:00.000Z"),
+      dateBeingChanged: "endDate",
+      draft,
+      origin: draft,
+    });
+
+    expect(result?.flippedTo).toBeNull();
+    expect(dayjs(result?.draft.values.schedule.end).format("YYYY-MM-DD")).toBe(
+      "2024-01-18",
+    );
+    expect(result?.hasMoved).toBe(true);
+  });
+
+  it("rejects a timed resize into another day", () => {
+    const draft = timedDraft();
+
+    expect(
+      resizeDraft({
+        currTime: dayjs("2024-01-16T12:00:00.000Z"),
+        dateBeingChanged: "endDate",
+        draft,
+        origin: draft,
+      }),
+    ).toBeNull();
+  });
+});
diff --git a/packages/web/src/views/Week/components/Draft/hooks/actions/draft-resize.util.ts b/packages/web/src/views/Week/components/Draft/hooks/actions/draft-resize.util.ts
new file mode 100644
index 000000000..f806321cd
--- /dev/null
+++ b/packages/web/src/views/Week/components/Draft/hooks/actions/draft-resize.util.ts
@@ -0,0 +1,126 @@
+import { YEAR_MONTH_DAY_FORMAT } from "@core/constants/date.constants";
+import dayjs, { type Dayjs } from "@core/util/date/dayjs";
+import {
+  type GridEventDraft,
+  type GridScheduleDraft,
+} from "@web/events/event-draft.types";
+import { replaceGridDraftSchedule } from "@web/events/grid-event-draft.adapter";
+import { GRID_TIME_STEP } from "@web/grid/grid.constants";
+
+type DateKey = "startDate" | "endDate";
+
+type DraftDates = Record<DateKey, string>;
+
+const formatDraftDate = (date: Date, isAllDay: boolean) =>
+  isAllDay ? dayjs(date).format(YEAR_MONTH_DAY_FORMAT) : dayjs(date).format();
+
+const datesFor = (draft: GridEventDraft, isAllDay: boolean): DraftDates => ({
+  startDate: formatDraftDate(draft.values.schedule.start, isAllDay),
+  endDate: formatDraftDate(draft.values.schedule.end, isAllDay),
+});
+
+export function isValidDraftResize(
+  currTime: Dayjs,
+  draft: GridEventDraft,
+  dateBeingChanged: DateKey,
+): boolean {
+  if (draft.values.schedule.kind === "allDay") return true;
+
+  const draftDate =
+    dateBeingChanged === "startDate"
+      ? draft.values.schedule.start
+      : draft.values.schedule.end;
+  const formattedCurrentTime = currTime.format();
+  if (dayjs(draftDate).format() === formattedCurrentTime) return false;
+
+  const diffDay = currTime.day() !== dayjs(draft.values.schedule.start).day();
+  if (diffDay) return false;
+
+  return formattedCurrentTime !== dayjs(draft.values.schedule.start).format();
+}
+
+export function resizeDraft({
+  currTime,
+  dateBeingChanged,
+  draft,
+  origin,
+}: {
+  currTime: Dayjs;
+  dateBeingChanged: DateKey;
+  draft: GridEventDraft;
+  origin: GridEventDraft;
+}): {
+  draft: GridEventDraft;
+  flippedTo: DateKey | null;
+  hasMoved: boolean;
+} | null {
+  if (!isValidDraftResize(currTime, draft, dateBeingChanged)) return null;
+
+  const isAllDay = draft.values.schedule.kind === "allDay";
+  const oppositeKey =
+    dateBeingChanged === "startDate" ? "endDate" : "startDate";
+  const draftDates = datesFor(draft, isAllDay);
+  const originDates = datesFor(origin, isAllDay);
+  let startDate = draftDates.startDate;
+  let endDate = draftDates.endDate;
+  let changedDate = dateBeingChanged;
+  let flippedTo: DateKey | null = null;
+
+  if (
+    dateBeingChanged === "startDate" &&
+    currTime.isAfter(dayjs(draftDates[oppositeKey]))
+  ) {
+    changedDate = oppositeKey;
+    startDate = draftDates.endDate;
+    flippedTo = changedDate;
+  } else if (
+    dateBeingChanged === "endDate" &&
+    currTime.isBefore(dayjs(draftDates[oppositeKey]))
+  ) {
+    changedDate = oppositeKey;
+    if (isAllDay) {
+      startDate = dayjs(startDate)
+        .subtract(1, "day")
+        .format(YEAR_MONTH_DAY_FORMAT);
+      endDate = dayjs(startDate).add(1, "day").format(YEAR_MONTH_DAY_FORMAT);
+    } else {
+      startDate = dayjs(startDate).subtract(GRID_TIME_STEP, "minutes").format();
+      endDate = dayjs(startDate).add(GRID_TIME_STEP, "minutes").format();
+    }
+    flippedTo = changedDate;
+  }
+
+  const workingSchedule: GridScheduleDraft = isAllDay
+    ? {
+        kind: "allDay",
+        start: dayjs(startDate).toDate(),
+        end: dayjs(endDate).toDate(),
+      }
+    : {
+        ...draft.values.schedule,
+        start: dayjs(startDate).toDate(),
+        end: dayjs(endDate).toDate(),
+      };
+  const workingDraft = replaceGridDraftSchedule(draft, workingSchedule);
+  const originTime = dayjs(originDates[changedDate]).subtract(1, "day");
+  const hasMoved = isAllDay
+    ? currTime.diff(originTime, "day", true) !== 0
+    : currTime.diff(originTime, "minute") !== 0;
+  const updatedTime = isAllDay
+    ? currTime
+        .add(changedDate === "endDate" ? 1 : 0, "day")
+        .format(YEAR_MONTH_DAY_FORMAT)
+    : originTime.add(currTime.diff(originTime, "minute"), "minutes").format();
+  const schedule: GridScheduleDraft = {
+    ...workingDraft.values.schedule,
+    ...(changedDate === "startDate"
+      ? { start: dayjs(updatedTime).toDate() }
+      : { end: dayjs(updatedTime).toDate() }),
+  } as GridScheduleDraft;
+
+  return {
+    draft: replaceGridDraftSchedule(workingDraft, schedule),
+    flippedTo,
+    hasMoved,
+  };
+}
diff --git a/packages/web/src/views/Week/components/Draft/hooks/actions/useDraftActions.ts b/packages/web/src/views/Week/components/Draft/hooks/actions/useDraftActions.ts
index c9f096084..2be2f9bc6 100644
--- a/packages/web/src/views/Week/components/Draft/hooks/actions/useDraftActions.ts
+++ b/packages/web/src/views/Week/components/Draft/hooks/actions/useDraftActions.ts
@@ -1,5 +1,4 @@
 import { useCallback, useMemo, useRef } from "react";
-import { YEAR_MONTH_DAY_FORMAT } from "@core/constants/date.constants";
 import { type RecurrenceScope } from "@core/types/event-command.contracts";
 import { devAlert } from "@core/util/app.util";
 import dayjs, { type Dayjs } from "@core/util/date/dayjs";
@@ -9,10 +8,7 @@ import { type PartialMouseEvent } from "@web/common/types/util.types";
 import { RecurringEventUpdateScope } from "@web/common/types/web.event.types";
 import { repositionDraftByKeyboard as applyDraftKeyboardReposition } from "@web/common/utils/draft/reposition-draft-by-keyboard.util";
 import { DirtyParser } from "@web/common/utils/parse/dirty.parser";
-import {
-  type GridEventDraft,
-  type GridScheduleDraft,
-} from "@web/events/event-draft.types";
+import { type GridEventDraft } from "@web/events/event-draft.types";
 import {
   parseGridEventDraft,
   replaceGridDraftSchedule,
@@ -23,7 +19,6 @@ import {
   selectDraftStatus,
   useDraftStore,
 } from "@web/events/stores/draft.store";
-import { GRID_TIME_STEP } from "@web/grid/grid.constants";
 import {
   clearGestureEphemera,
   useDraftEffects,
@@ -37,6 +32,7 @@ import {
 import { type DateCalcs } from "@web/views/Week/hooks/grid/useDateCalcs";
 import { type WeekProps } from "@web/views/Week/hooks/useWeek";
 import { resolveDraftDragSchedule } from "./draft-drag-schedule.util";
+import { resizeDraft } from "./draft-resize.util";
 
 const scopeFromApplyTo = (
   applyTo: RecurringEventUpdateScope,
@@ -315,133 +311,12 @@ export const useDraftActions = (
     [applyDragPosition, dragOffset, dragStatus, isDragging],
   );
 
-  const isValidMovement = useCallback(
-    (currTime: dayjs.Dayjs, liveDraft: GridEventDraft) => {
-      if (!dateBeingChanged) return false;
-
-      const isAllDay = liveDraft.values.schedule.kind === "allDay";
-      if (isAllDay) {
-        return true;
-      }
-
-      const draftDate =
-        dateBeingChanged === "startDate"
-          ? liveDraft.values.schedule.start
-          : liveDraft.values.schedule.end;
-      const _currTime = currTime.format();
-      const noChange = dayjs(draftDate).format() === _currTime;
-
-      if (noChange) return false;
-
-      const diffDay =
-        currTime.day() !== dayjs(liveDraft.values.schedule.start).day();
-      if (diffDay) return false;
-
-      const sameStart =
-        _currTime === dayjs(liveDraft.values.schedule.start).format();
-      if (sameStart) return false;
-
-      return true;
-    },
-    [dateBeingChanged],
-  );
-
   const resize = useCallback(
     (e: MouseEvent) => {
       const liveDraft = readLiveDraft();
       // Freeze the origin against the gesture snapshot so live store updates
       // mid-gesture must not shift the resize baseline.
-      if (!liveDraft || !gestureOriginDraft) return;
-
-      const isAllDay = liveDraft.values.schedule.kind === "allDay";
-      const _dateBeingChanged = dateBeingChanged as "startDate" | "endDate";
-      const oppositeKey =
-        _dateBeingChanged === "startDate" ? "endDate" : "startDate";
-
-      // String mirrors of the draft's live schedule, formatted exactly as
-      // the legacy GridEvent draft stored them (all-day: day-only
-      // YEAR_MONTH_DAY_FORMAT strings; timed: full offset strings). The flip
-      // math below is unchanged dayjs-string arithmetic ported verbatim from
-      // before the GridEventDraft conversion, reading/writing through this
-      // mirror instead of native GridEvent fields.
-      const formatDraftDate = (date: Date) =>
-        isAllDay
-          ? dayjs(date).format(YEAR_MONTH_DAY_FORMAT)
-          : dayjs(date).format();
-      const draftDates: Record<"startDate" | "endDate", string> = {
-        startDate: formatDraftDate(liveDraft.values.schedule.start),
-        endDate: formatDraftDate(liveDraft.values.schedule.end),
-      };
-      const originDates: Record<"startDate" | "endDate", string> = {
-        startDate: formatDraftDate(gestureOriginDraft.values.schedule.start),
-        endDate: formatDraftDate(gestureOriginDraft.values.schedule.end),
-      };
-
-      let workingDraft = liveDraft;
-      let workingDateBeingChanged = dateBeingChanged;
-
-      const flipIfNeeded = (currTime: Dayjs) => {
-        let startDate = draftDates.startDate;
-        let endDate = draftDates.endDate;
-
-        let justFlipped = false;
-        let dateKey = workingDateBeingChanged;
-        const opposite = dayjs(draftDates[oppositeKey]);
-        const comparisonKeyword =
-          workingDateBeingChanged === "startDate" ? "after" : "before";
-
-        if (comparisonKeyword === "after") {
-          if (currTime.isAfter(opposite)) {
-            dateKey = oppositeKey;
-            startDate = draftDates.endDate;
-            workingDateBeingChanged = dateKey;
-            setDateBeingChanged(dateKey);
-
-            justFlipped = true;
-          }
-        } else if (comparisonKeyword === "before") {
-          if (currTime.isBefore(opposite)) {
-            workingDateBeingChanged = oppositeKey;
-            setDateBeingChanged(oppositeKey);
-            if (isAllDay) {
-              // For all-day events, move by day
-              startDate = dayjs(startDate)
-                .subtract(1, "day")
-                .format(YEAR_MONTH_DAY_FORMAT);
-              endDate = dayjs(startDate)
-                .add(1, "day")
-                .format(YEAR_MONTH_DAY_FORMAT);
-            } else {
-              // For timed events, move by time step
-              startDate = dayjs(startDate)
-                .subtract(GRID_TIME_STEP, "minutes")
-                .format();
-              endDate = dayjs(startDate)
-                .add(GRID_TIME_STEP, "minutes")
-                .format();
-            }
-
-            justFlipped = true;
-          }
-        }
-
-        setIsFormOpen(false);
-
-        const schedule: GridScheduleDraft = isAllDay
-          ? {
-              kind: "allDay",
-              start: dayjs(startDate).toDate(),
-              end: dayjs(endDate).toDate(),
-            }
-          : {
-              ...workingDraft.values.schedule,
-              start: dayjs(startDate).toDate(),
-              end: dayjs(endDate).toDate(),
-            };
-
-        workingDraft = replaceGridDraftSchedule(workingDraft, schedule);
-        return justFlipped;
-      };
+      if (!liveDraft || !gestureOriginDraft || !dateBeingChanged) return;
 
       e.preventDefault();
       e.stopPropagation();
@@ -449,60 +324,33 @@ export const useDraftActions = (
       if (!isResizing) return;
 
       // For all-day events, use a fixed Y coordinate (0) because Y positioning is irrelevant:
-      const y = isAllDay ? 0 : e.clientY;
+      const y = liveDraft.values.schedule.kind === "allDay" ? 0 : e.clientY;
       const currTime = dateCalcs.getDateByXY(
         e.clientX,
         y,
         weekProps.component.startOfView,
       );
 
-      if (!isValidMovement(currTime, workingDraft)) {
-        return;
-      }
-
-      const justFlipped = flipIfNeeded(currTime);
-      const dateChanged = justFlipped ? oppositeKey : _dateBeingChanged;
-
-      const origTime = dayjs(originDates[dateChanged]).add(-1, "day");
-
-      let updatedTime: string;
-      let hasMoved: boolean;
-
-      if (isAllDay) {
-        // For all-day events, work with day differences
-        const diffDays = currTime.diff(origTime, "day", true);
-        updatedTime = currTime
-          .add(dateChanged === "endDate" ? 1 : 0, "day")
-          .format(YEAR_MONTH_DAY_FORMAT);
-        hasMoved = diffDays !== 0;
-      } else {
-        // For timed events, work with minute differences
-        const diffMin = currTime.diff(origTime, "minute");
-        updatedTime = origTime.add(diffMin, "minutes").format();
-        hasMoved = diffMin !== 0;
-      }
+      const result = resizeDraft({
+        currTime,
+        dateBeingChanged,
+        draft: liveDraft,
+        origin: gestureOriginDraft,
+      });
+      if (!result) return;
 
-      if (!resizeStatus?.hasMoved && hasMoved) {
+      setIsFormOpen(false);
+      if (result.flippedTo) setDateBeingChanged(result.flippedTo);
+      if (!resizeStatus?.hasMoved && result.hasMoved) {
         setResizeStatus({ hasMoved: true });
       }
-
-      const nextSchedule: GridScheduleDraft = {
-        ...workingDraft.values.schedule,
-        ...(dateChanged === "startDate"
-          ? { start: dayjs(updatedTime).toDate() }
-          : { end: dayjs(updatedTime).toDate() }),
-      } as GridScheduleDraft;
-
-      draftActions.setGridDraft(
-        replaceGridDraftSchedule(workingDraft, nextSchedule),
-      );
+      draftActions.setGridDraft(result.draft);
     },
     [
       dateBeingChanged,
       dateCalcs,
       gestureOriginDraft,
       isResizing,
-      isValidMovement,
       resizeStatus?.hasMoved,
       setDateBeingChanged,
       setIsFormOpen,