fix: date-picker bug for negative UTC timezones

frontend/src/components/DatePicker/DatePickerContext.tsx

@@ -20,7 +20,6 @@ import {
   useMultiStyleConfig,
 } from '@chakra-ui/react'
 import { format, isValid, parse } from 'date-fns'
-import { zonedTimeToUtc } from 'date-fns-tz'
 
 import { ThemeColorScheme } from '~theme/foundations/colours'
 import { useIsMobile } from '~hooks/useIsMobile'
@@ -84,7 +83,6 @@ const useProvideDatePicker = ({
   isReadOnly: isReadOnlyProp,
   isRequired: isRequiredProp,
   isInvalid: isInvalidProp,
-  timeZone = 'UTC',
   locale,
   isDateUnavailable,
   allowManualInput = true,
@@ -120,9 +118,9 @@ const useProvideDatePicker = ({
   const formatInputValue = useCallback(
     (date: Date | null) => {
       if (!date || !isValid(date)) return ''
-      return format(zonedTimeToUtc(date, timeZone), displayFormat, { locale })
+      return format(date, displayFormat, { locale })
     },
-    [displayFormat, locale, timeZone],
+    [displayFormat, locale],
   )
 
   // What is rendered as a string in the input according to given display format.
@@ -142,11 +140,7 @@ const useProvideDatePicker = ({
 
   const handleInputBlur: FocusEventHandler<HTMLInputElement> = useCallback(
     (e) => {
-      const date = parse(
-        internalInputValue,
-        dateFormat,
-        zonedTimeToUtc(new Date(), timeZone),
-      )
+      const date = parse(internalInputValue, dateFormat, new Date())
       // Clear if input is invalid on blur if invalid dates are not allowed.
       if (!allowInvalidDates && !isValid(date)) {
         setInternalValue(null)
@@ -161,7 +155,6 @@ const useProvideDatePicker = ({
       onBlur,
       setInternalInputValue,
       setInternalValue,
-      timeZone,
     ],
   )
 
@@ -179,12 +172,11 @@ const useProvideDatePicker = ({
 
   const handleDateChange = useCallback(
     (date: Date | null) => {
-      const zonedDate = date ? zonedTimeToUtc(date, timeZone) : null
-      if (allowInvalidDates || isValid(zonedDate) || !zonedDate) {
-        setInternalValue(zonedDate)
+      if (allowInvalidDates || isValid(date) || !date) {
+        setInternalValue(date)
       }
-      if (zonedDate) {
-        setInternalInputValue(format(zonedDate, displayFormat, { locale }))
+      if (date) {
+        setInternalInputValue(format(date, displayFormat, { locale }))
       } else {
         setInternalInputValue('')
       }
@@ -198,23 +190,18 @@ const useProvideDatePicker = ({
       locale,
       setInternalInputValue,
       setInternalValue,
-      timeZone,
     ],
   )
 
   const handleInputChange = useCallback(
     (event: React.ChangeEvent<HTMLInputElement>) => {
-      const date = parse(
-        event.target.value,
-        dateFormat,
-        zonedTimeToUtc(new Date(), timeZone),
-      )
+      const date = parse(event.target.value, dateFormat, new Date())
       setInternalInputValue(event.target.value)
       if (isValid(date)) {
         setInternalValue(date)
       }
     },
-    [dateFormat, setInternalInputValue, setInternalValue, timeZone],
+    [dateFormat, setInternalInputValue, setInternalValue],
   )
 
   const handleInputClick: MouseEventHandler<HTMLInputElement> = useCallback(

frontend/src/components/DatePicker/types.ts

@@ -33,10 +33,4 @@ export interface DatePickerBaseProps
   refocusOnClose?: boolean
   /** date-fns's Locale of the date to be applied if provided. */
   locale?: Locale
-  /**
-   * Time zone of date created.
-   * Defaults to `'UTC'`.
-   * Accepts all possible `Intl.Locale.prototype.timeZones` values
-   */
-  timeZone?: string
 }

frontend/src/components/DateRangePicker/DateRangePickerContext.tsx

@@ -21,7 +21,6 @@ import {
   useMultiStyleConfig,
 } from '@chakra-ui/react'
 import { format, isValid, parse } from 'date-fns'
-import { zonedTimeToUtc } from 'date-fns-tz'
 
 import { ThemeColorScheme } from '~theme/foundations/colours'
 import { useIsMobile } from '~hooks/useIsMobile'
@@ -92,7 +91,6 @@ const useProvideDateRangePicker = ({
   isReadOnly: isReadOnlyProp,
   isRequired: isRequiredProp,
   isInvalid: isInvalidProp,
-  timeZone = 'UTC',
   locale,
   isDateUnavailable,
   allowManualInput = true,
@@ -129,13 +127,13 @@ const useProvideDateRangePicker = ({
   // What is rendered as a string in the start date range input according to given display format.
   const [startInputDisplay, setStartInputDisplay] = useState(
     startDate && isValid(startDate)
-      ? format(zonedTimeToUtc(startDate, timeZone), displayFormat, { locale })
+      ? format(startDate, displayFormat, { locale })
       : '',
   )
   // What is rendered as a string in the end date range input according to given display format.
   const [endInputDisplay, setEndInputDisplay] = useState(
     endDate && isValid(endDate)
-      ? format(zonedTimeToUtc(endDate, timeZone), displayFormat, { locale })
+      ? format(endDate, displayFormat, { locale })
       : '',
   )
 
@@ -151,24 +149,18 @@ const useProvideDateRangePicker = ({
       ) as DateRangeValue
 
       const [nextStart, nextEnd] = sortedRange
-      const zonedStartDate = nextStart
-        ? zonedTimeToUtc(nextStart, timeZone)
-        : null
-      const zonedEndDate = nextEnd ? zonedTimeToUtc(nextEnd, timeZone) : null
-      if (zonedStartDate) {
-        if (isValid(zonedStartDate)) {
-          setStartInputDisplay(
-            format(zonedStartDate, displayFormat, { locale }),
-          )
+      if (nextStart) {
+        if (isValid(nextStart)) {
+          setStartInputDisplay(format(nextStart, displayFormat, { locale }))
         } else if (!allowInvalidDates) {
           setStartInputDisplay('')
         }
       } else {
         setStartInputDisplay('')
       }
-      if (zonedEndDate) {
-        if (isValid(zonedEndDate)) {
-          setEndInputDisplay(format(zonedEndDate, displayFormat, { locale }))
+      if (nextEnd) {
+        if (isValid(nextEnd)) {
+          setEndInputDisplay(format(nextEnd, displayFormat, { locale }))
         } else if (!allowInvalidDates) {
           setEndInputDisplay('')
         }
@@ -177,7 +169,7 @@ const useProvideDateRangePicker = ({
       }
       setInternalValue(validRange)
     },
-    [allowInvalidDates, displayFormat, locale, setInternalValue, timeZone],
+    [allowInvalidDates, displayFormat, locale, setInternalValue],
   )
 
   const fcProps = useFormControlProps({
@@ -274,11 +266,8 @@ const useProvideDateRangePicker = ({
 
   const handleCalendarDateChange = useCallback(
     (date: DateRangeValue) => {
-      const zonedDateRange = date.map((d) =>
-        d ? zonedTimeToUtc(d, timeZone) : null,
-      ) as DateRangeValue
-      const [nextStartDate, nextEndDate] = zonedDateRange
-      setInternalValue(zonedDateRange)
+      const [nextStartDate, nextEndDate] = date
+      setInternalValue(date)
       setStartInputDisplay(
         nextStartDate ? format(nextStartDate, displayFormat, { locale }) : '',
       )
@@ -296,7 +285,6 @@ const useProvideDateRangePicker = ({
       displayFormat,
       locale,
       setInternalValue,
-      timeZone,
     ],
   )
 

frontend/src/features/admin-form/create/builder-and-design/BuilderAndDesignDrawer/EditFieldDrawer/edit-fieldtype/EditDate/EditDate.tsx

@@ -1,4 +1,4 @@
-import { useMemo } from 'react'
+import { useCallback, useMemo } from 'react'
 import { Controller, RegisterOptions } from 'react-hook-form'
 import { Box, FormControl, SimpleGrid } from '@chakra-ui/react'
 import { isBefore, isEqual, isValid } from 'date-fns'
@@ -10,7 +10,11 @@ import {
   DateValidationOptions,
 } from '~shared/types/field'
 
-import { fromUtcToLocalDate, isDateOutOfRange } from '~utils/date'
+import {
+  isDateOutOfRange,
+  loadDateFromNormalizedDate,
+  normalizeDateToUtc,
+} from '~utils/date'
 import { createBaseValidationRules } from '~utils/fieldValidation'
 import { DatePicker } from '~components/DatePicker'
 import { SingleSelect } from '~components/Dropdown'
@@ -49,10 +53,10 @@ const transformDateFieldToEditForm = (field: DateFieldBase): EditDateInputs => {
     selectedDateValidation:
       field.dateValidation.selectedDateValidation ?? ('' as const),
     customMaxDate: field.dateValidation.selectedDateValidation
-      ? field.dateValidation.customMaxDate ?? null
+      ? loadDateFromNormalizedDate(field.dateValidation.customMaxDate)
       : null,
     customMinDate: field.dateValidation.selectedDateValidation
-      ? field.dateValidation.customMinDate ?? null
+      ? loadDateFromNormalizedDate(field.dateValidation.customMinDate)
       : null,
   }
   return {
@@ -97,6 +101,25 @@ const transformDateEditFormToField = (
 }
 
 export const EditDate = ({ field }: EditDateProps): JSX.Element => {
+  const preSubmitTransform = useCallback(
+    (inputs: EditDateInputs, output: DateFieldBase): DateFieldBase => {
+      // normalize time to UTC before saving
+      return {
+        ...output,
+        dateValidation: {
+          ...inputs.dateValidation,
+          customMinDate: normalizeDateToUtc(
+            inputs.dateValidation.customMinDate,
+          ),
+          customMaxDate: normalizeDateToUtc(
+            inputs.dateValidation.customMaxDate,
+          ),
+        },
+      } as DateFieldBase
+    },
+    [],
+  )
+
   const {
     register,
     formState: { errors },
@@ -111,6 +134,7 @@ export const EditDate = ({ field }: EditDateProps): JSX.Element => {
     transform: {
       input: transformDateFieldToEditForm,
       output: transformDateEditFormToField,
+      preSubmit: preSubmitTransform,
     },
   })
 
@@ -222,9 +246,7 @@ export const EditDate = ({ field }: EditDateProps): JSX.Element => {
                       isDateUnavailable={(d) =>
                         isDateOutOfRange(
                           d,
-                          fromUtcToLocalDate(
-                            getValues('dateValidation.customMinDate'),
-                          ),
+                          getValues('dateValidation.customMinDate'),
                         )
                       }
                       {...field}

frontend/src/templates/Field/Date/DateField.tsx

@@ -5,10 +5,10 @@ import { FormColorTheme } from '~shared/types'
 import { DateSelectedValidation } from '~shared/types/field'
 
 import {
-  fromUtcToLocalDate,
   isDateAfterToday,
   isDateBeforeToday,
   isDateOutOfRange,
+  loadDateFromNormalizedDate,
 } from '~utils/date'
 import { createDateValidationRules } from '~utils/fieldValidation'
 import { DatePicker } from '~components/DatePicker'
@@ -53,8 +53,8 @@ export const DateField = ({
           // need to convert to local time but with the same date as UTC.
           return isDateOutOfRange(
             date,
-            fromUtcToLocalDate(customMinDate),
-            fromUtcToLocalDate(customMaxDate),
+            loadDateFromNormalizedDate(customMinDate),
+            loadDateFromNormalizedDate(customMaxDate),
           )
         }
         default:

frontend/src/utils/date.ts

@@ -38,8 +38,12 @@ export const isDateAfterToday = (date: number | Date) => {
   return isAfter(date, endOfToday())
 }
 
-// Converts UTC time to the same date in local time, ignoring original timezone.
-export const fromUtcToLocalDate = (date?: Date | null) => {
+export const normalizeDateToUtc = (date: Date | null) => {
+  if (!date) return date
+  return Date.UTC(date.getFullYear(), date.getMonth(), date.getDate())
+}
+
+export const loadDateFromNormalizedDate = (date: Date | null) => {
   if (!date) return date
   return new Date(date.getUTCFullYear(), date.getUTCMonth(), date.getUTCDate())
 }

frontend/src/utils/fieldValidation.ts

@@ -53,10 +53,10 @@ import {
 import { VerifiableFieldBase } from '~features/verifiable-fields/types'
 
 import {
-  fromUtcToLocalDate,
   isDateAfterToday,
   isDateBeforeToday,
   isDateOutOfRange,
+  loadDateFromNormalizedDate,
 } from './date'
 import { formatNumberToLocaleString } from './stringFormat'
 
@@ -434,8 +434,8 @@ export const createDateValidationRules: ValidationRuleFn<DateFieldBase> = (
         return (
           !isDateOutOfRange(
             parseDate(val),
-            fromUtcToLocalDate(customMinDate),
-            fromUtcToLocalDate(customMaxDate),
+            loadDateFromNormalizedDate(customMinDate),
+            loadDateFromNormalizedDate(customMaxDate),
           ) || 'Selected date is not within the allowed date range'
         )
       },

src/app/utils/field-validation/validators/dateValidator.ts

@@ -42,10 +42,8 @@ const dateFormatValidator: DateValidator = (response) => {
  */
 const pastOnlyValidator: DateValidator = (response) => {
   // Today takes two possible values - a min (in makeFutureOnlyValidator) and max (here)
-  // Add 14 hours here to account for up to UTC + 14 timezone
-  // This allows validation to pass as long as user is on the correct date (locally)
-  // Even if they are in a different timezone
-  const todayMax = moment().utc().add(14, 'hours').startOf('day')
+  // Dates are converted to use local timezones when loaded by the DateField so no conversion required
+  const todayMax = moment()
   const { answer } = response
   const answerDate = createMomentFromDateString(answer)
 
@@ -59,10 +57,8 @@ const pastOnlyValidator: DateValidator = (response) => {
  */
 const futureOnlyValidator: DateValidator = (response) => {
   // Today takes two possible values - a min (here) and max (in makePastOnlyValidator)
-  // Subtract 12 hours here to account for up to UTC - 12 timezone
-  // This allows validation to pass as long as user is on the correct date (locally)
-  // Even if they are in a different timezone
-  const todayMin = moment().utc().subtract(12, 'hours').startOf('day')
+  // Dates are converted to use local timezones when loaded by the DateField so no conversion required
+  const todayMin = moment()
   const { answer } = response
   const answerDate = createMomentFromDateString(answer)