#1192 start date bug by jasonk55 · Pull Request #3615 · Northeastern-Electric-Racing/FinishLine

jasonk55 · 2025-09-24T18:06:17Z

Changes

Fix start date off-by-one bug by normalizing client-provided dates to the user’s local midnight converted to UTC before persisting.

Notes

This change is timezone agnostic, so if someone in another timezone chooses a day (e.g. 9/24/25) for the start date, this is the date for everyone else.

To Do

Any remaining things that need to get done

Make the frontend render the date correctly according to user's timezone

Checklist

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Closes #1192

src/backend/src/controllers/work-packages.controllers.ts

src/backend/src/services/work-packages.services.ts

…n-Electric-Racing/FinishLine into #1192-start-date-bug

gcooper407

thanks for making those fixes, looks good!

walker-sean

Can we make this standard for how we handle dates in the frontend and backend to avoid this issue in other places

src/backend/src/services/work-packages.services.ts

Copilot

Pull request overview

Fixes the “start date shifts to next day” timezone bug by standardizing how date-only selections are normalized and persisted (moving toward storing/transporting dates as UTC-midnight for the intended calendar day).

Changes:

Added shared UTC-midnight date helpers and started applying them across frontend date flows.
Removed backend “+12 hours” workaround and now parses incoming start dates directly.
Updated frontend date formatting/Day.js usage and bumped Day.js versions/deps to support the new utilities.

Reviewed changes

Copilot reviewed 14 out of 15 changed files in this pull request and generated 12 comments.

Show a summary per file

File	Description
yarn.lock	Updates lockfile for Day.js range changes across workspaces.
src/shared/src/date-utils.ts	Adds UTC-midnight/date normalization helpers (used by frontend).
src/shared/package.json	Adds Day.js dependency to shared package.
src/frontend/src/utils/pipes.ts	Adjusts `datePipe` to avoid previous Date normalization approach.
src/frontend/src/utils/datetime.utils.ts	Switches `transformDate` to Day.js formatting.
src/frontend/src/pages/WorkPackageForm/WorkPackageFormView.tsx	Normalizes submitted work package start date.
src/frontend/src/pages/ProjectDetailPage/ProjectViewContainer/TaskList/v2/TaskCard.tsx	Normalizes task deadline/start date during edit.
src/frontend/src/pages/ProjectDetailPage/ProjectViewContainer/TaskList/TaskFormModal.tsx	Normalizes task form dates and adjusts DatePicker defaults.
src/frontend/src/pages/FinancePage/FinanceDashboard/GeneralFinanceDashboard.tsx	Normalizes DatePicker-selected finance filter dates.
src/frontend/src/pages/FinancePage/FinanceDashboard/AdminFinanceDashboard.tsx	Normalizes DatePicker-selected finance filter dates.
src/frontend/src/pages/CalendarPage/UpcomingMeetingsCard.tsx	Normalizes displayed meeting date.
src/frontend/src/pages/CalendarPage/CalendarPage.tsx	Normalizes event bucketing and removes prior timezone-offset hacks.
src/frontend/src/apis/work-packages.api.ts	Simplifies axios payload posting.
src/frontend/package.json	Bumps Day.js version in frontend.
src/backend/src/services/work-packages.services.ts	Removes “+12 hours” hack and parses start date directly.

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

src/frontend/src/pages/ProjectDetailPage/ProjectViewContainer/TaskList/TaskFormModal.tsx

Copilot · 2026-03-03T17:03:38Z

src/frontend/src/pages/ProjectDetailPage/ProjectViewContainer/TaskList/v2/TaskCard.tsx

+        deadline: deadline ? dateToUtcMidnight(deadline) : undefined,
+        startDate: startDate ? dateToUtcMidnight(startDate) : undefined,


handleEditTask normalizes deadline/startDate with dateToUtcMidnight, but TaskFormModal already normalizes these fields before calling onSubmit. Normalizing twice is not idempotent across timezones (a UTC-midnight Date can appear as the previous day locally, so the second normalization can shift the day). Ensure the UTC-midnight conversion happens exactly once (either here or in the modal).

Suggested change

deadline: deadline ? dateToUtcMidnight(deadline) : undefined,

startDate: startDate ? dateToUtcMidnight(startDate) : undefined,

deadline: deadline ?? undefined,

startDate: startDate ?? undefined,

Copilot · 2026-03-03T17:03:38Z

src/frontend/src/pages/FinancePage/FinanceDashboard/GeneralFinanceDashboard.tsx

      <DatePicker
        label="End Date"
        value={endDateState}
        minDate={startDateState || undefined}
        shouldDisableDate={(date) => (startDateState ? date < startDateState : false)}
        slotProps={{
          textField: {
            size: 'small',
            sx: datePickerStyle
          },
          field: { clearable: true }
        }}
-        onChange={(newValue: Date | null) => setEndDateState(newValue ?? undefined)}
+        onChange={(newValue: Date | null) => setEndDateState(newValue ? dateToUtcMidnight(newValue) : undefined)}
      />


Same issue for the end date: persisting dateToUtcMidnight(newValue) into endDateState can cause the DatePicker to render an off-by-one day in non-UTC timezones. Keep local DatePicker dates in state (and normalize only when constructing API params), or re-wrap the UTC date into a local calendar-day Date for the picker.

Copilot · 2026-03-03T17:03:39Z

src/frontend/src/pages/FinancePage/FinanceDashboard/AdminFinanceDashboard.tsx

      <DatePicker
        label="Start Date"
        value={startDateState}
        maxDate={endDateState || undefined}
        shouldDisableDate={(date) => (endDateState ? date > endDateState : false)}
        slotProps={{
          textField: {
            size: 'small',
            sx: datePickerStyle
          },
          field: { clearable: true }
        }}
-        onChange={(newValue: Date | null) => setStartDateState(newValue ?? undefined)}
+        onChange={(newValue: Date | null) => setStartDateState(newValue ? dateToUtcMidnight(newValue) : undefined)}
      />


Storing dateToUtcMidnight(newValue) directly into the DatePicker value can make the picker display the wrong day for users not in UTC, since the DatePicker renders using local time. Prefer keeping the local DatePicker selection in state and converting to UTC midnight only when building the API/query params (or convert back to a local calendar-day Date before passing into value).

Copilot · 2026-03-03T17:03:39Z

src/frontend/src/pages/FinancePage/FinanceDashboard/AdminFinanceDashboard.tsx

          field: { clearable: true }
        }}
-        onChange={(newValue: Date | null) => setEndDateState(newValue ?? undefined)}
+        onChange={(newValue: Date | null) => setEndDateState(newValue ? dateToUtcMidnight(newValue) : undefined)}


Same issue for the end date: setting endDateState to dateToUtcMidnight(newValue) can cause the DatePicker to show an off-by-one day depending on timezone. Keep local DatePicker values in state and normalize at the request boundary, or re-wrap UTC dates into local calendar-day Dates for display.

Suggested change

onChange={(newValue: Date | null) => setEndDateState(newValue ? dateToUtcMidnight(newValue) : undefined)}

onChange={(newValue: Date | null) => setEndDateState(newValue ?? undefined)}

Copilot · 2026-03-03T17:03:40Z

src/frontend/src/pages/ProjectDetailPage/ProjectViewContainer/TaskList/TaskFormModal.tsx

+          handleSubmit((data) => {
+            const transformedData: EditTaskFormInput = {
+              ...data,
+              startDate: data.startDate ? dateToUtcMidnight(data.startDate) : undefined,
+              deadline: data.deadline ? dateToUtcMidnight(data.deadline) : undefined
+            };
+            onSubmit(transformedData);
+          })(e);


The modal is converting startDate/deadline to UTC-midnight before calling onSubmit. That changes the meaning of the form values for callers that expect local DatePicker dates (e.g. task creation currently formats the returned Date into a date-only string). It also causes double-normalization in the edit flow (TaskCard normalizes again), which can shift the day backwards in some timezones. Prefer keeping the form values as local Dates and performing UTC normalization at the API boundary (or ensure normalization happens exactly once).

Copilot · 2026-03-03T17:03:40Z

src/frontend/src/pages/FinancePage/FinanceDashboard/GeneralFinanceDashboard.tsx

      <DatePicker
        label="Start Date"
        value={startDateState}
        maxDate={endDateState || undefined}
        shouldDisableDate={(date) => (endDateState ? date > endDateState : false)}
        slotProps={{
          textField: {
            size: 'small',
            sx: datePickerStyle
          },
          field: { clearable: true }
        }}
-        onChange={(newValue: Date | null) => setStartDateState(newValue ?? undefined)}
+        onChange={(newValue: Date | null) => setStartDateState(newValue ? dateToUtcMidnight(newValue) : undefined)}
      />


Storing dateToUtcMidnight(newValue) directly into the DatePicker value can make the picker display the previous/next day for users not in UTC, because the picker renders based on the local timezone of the Date object. Consider keeping startDateState as the local DatePicker value and only converting to UTC midnight when building request/query parameters (or convert back to a local “calendar day” Date before passing into value).

Copilot · 2026-03-03T17:03:40Z

src/frontend/src/pages/CalendarPage/CalendarPage.tsx

-                                    datePipe(new Date(cardDate.getTime() + cardDate.getTimezoneOffset() * 60000))
-                                  ) ?? []
-                                }
+                                tasks={taskDict.get(datePipe(cardDate)) ?? []}


The tasks lookup uses the same datePipe(cardDate) key as events/dayOfWeek. If the card key should represent the user’s selected calendar day (timezone-agnostic), normalize cardDate to UTC midnight (preserving local calendar day) before calling datePipe, otherwise tasks can appear under the wrong day in some timezones.

Copilot · 2026-03-03T17:03:41Z

src/shared/src/date-utils.ts

+ * @returns Date object representing today at UTC midnight
+ */
+export const getCurrentUtcMidnight = (): Date => {
+  return dayjs().startOf('day').utc().toDate();


getCurrentUtcMidnight does not currently return UTC midnight: dayjs().startOf('day').utc() computes local midnight and then converts that instant to UTC, which can be a non-midnight UTC time. If the intent is “today at 00:00 UTC”, build it in UTC (e.g., start from dayjs.utc() / call .utc() before .startOf('day')).

Suggested change

return dayjs().startOf('day').utc().toDate();

return dayjs.utc().startOf('day').toDate();

Copilot · 2026-03-03T17:03:41Z

src/frontend/src/utils/pipes.ts

@@ -76,8 +76,8 @@ export const emDashPipe = (str: string) => {
 */
 export const datePipe = (date?: Date, includeYear = true) => {


datePipe’s parameter is typed as Date, but the implementation explicitly handles string values (typeof date === 'string'). This will either be dead code (if TS prevents string callers) or cause type errors where datePipe is called with a string. Consider updating the signature to accept Date | string (or removing the string branch) so the type matches actual usage.

Suggested change

export const datePipe = (date?: Date, includeYear = true) => {

export const datePipe = (date?: Date | string, includeYear = true) => {

jasonk55 added 2 commits September 24, 2025 00:17

working fix for start date bug

36206c8

#1192 fixed file versions

c3f8e64

jasonk55 requested review from chpy04 and superhvarn September 24, 2025 18:06

jasonk55 self-assigned this Sep 24, 2025

superhvarn requested changes Sep 24, 2025

View reviewed changes

src/backend/src/controllers/work-packages.controllers.ts Outdated Show resolved Hide resolved

src/backend/src/services/work-packages.services.ts Outdated Show resolved Hide resolved

jasonk55 added 5 commits September 24, 2025 19:01

#1192 Fixed controllers file

57e4840

1192 Date is the same anywhere

af942d8

#1192 Cleaned up controller methods

ce10efb

#1192 Date stays the same in all timezones

e53ee7d

Merge branch '#1192-start-date-bug' of https://github.com/Northeaster…

b3d755e

…n-Electric-Racing/FinishLine into #1192-start-date-bug

gcooper407 self-requested a review September 29, 2025 17:49

gcooper407 previously approved these changes Sep 29, 2025

View reviewed changes

dayjs

1a9095c

superhvarn dismissed gcooper407’s stale review via 1a9095c October 16, 2025 23:38

superhvarn added 4 commits October 16, 2025 19:39

prettier

fe522fa

getting rid of the offset

bbe0d3c

prettier

0b3b8ae

syntax error

f2f7703

superhvarn self-assigned this Oct 23, 2025

Merge branch 'develop' into #1192-start-date-bug

6dbb5ef

walker-sean requested changes Oct 29, 2025

View reviewed changes

src/backend/src/services/work-packages.services.ts Outdated Show resolved Hide resolved

superhvarn and others added 8 commits November 5, 2025 18:47

new date utils

73dc4a7

#1192 prettier

c0a625d

#1192 prettier

bf2a3b3

#1192 applying date method in finance

c3829c6

#1192 prettier

b04d683

Merge branch 'develop' into #1192-start-date-bug

5b6db41

#1192 merge updates and adding package

1eaed57

#1192 tasks preserve submitters date

3e20d9d

cielbellerose added 3 commits February 16, 2026 21:02

Merge branch 'develop' into #1192-start-date-bug

6683304

#1192 updated wp date + package fix

5912dfd

#1192 remove yarn lock changes

b106aa6

cielbellerose self-assigned this Feb 28, 2026

cielbellerose added 4 commits February 28, 2026 12:14

Merge branch 'develop' into #1192-start-date-bug

b0e3a13

#1192 yarn lock fix

ce00072

#1192 calendar date time fixes

ec9be84

#1192 edit task fix

2814b4a

chpy04 requested a review from Copilot March 3, 2026 16:55

Copilot started reviewing on behalf of chpy04 March 3, 2026 16:55 View session

Copilot AI reviewed Mar 3, 2026

View reviewed changes

		deadline: deadline ? dateToUtcMidnight(deadline) : undefined,
		startDate: startDate ? dateToUtcMidnight(startDate) : undefined,

	onChange={(newValue: Date \| null) => setEndDateState(newValue ? dateToUtcMidnight(newValue) : undefined)}
	onChange={(newValue: Date \| null) => setEndDateState(newValue ?? undefined)}

	return dayjs().startOf('day').utc().toDate();
	return dayjs.utc().startOf('day').toDate();

		@@ -76,8 +76,8 @@ export const emDashPipe = (str: string) => {
		*/
		export const datePipe = (date?: Date, includeYear = true) => {

	export const datePipe = (date?: Date, includeYear = true) => {
	export const datePipe = (date?: Date \| string, includeYear = true) => {

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jasonk55 commented Sep 24, 2025 •

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