Fix filter date round-trip: parse calendar day, ignore stored tz marker

The respect=false wire format ('YYYY-MM-DDT00:00:00Z') made the filter's display
round-trip drop a day in browsers west of UTC: dayjs(stored).startOf('day') parses the
Z-marked instant in browser-local time, which moves the picker's value to the previous
calendar day after any re-render.

Adds parseFilterDate as the inverse of formatFilterDate — slices the calendar prefix
from the stored value and rebuilds a browser-local midnight timestamp, so the picker
re-shows the same day the user clicked regardless of host TZ. Locked down with
round-trip tests against both wire formats (Z marker and signed offset).

Author: markus-moser

assets/js/src/core/components/date-picker/utils/date-picker-utils.test.ts

@@ -11,7 +11,7 @@
 import dayjs from 'dayjs'
 import utc from 'dayjs/plugin/utc'
 import timezone from 'dayjs/plugin/timezone'
-import { toDayJs, fromDayJs, toServerWallClock, formatFilterDate } from './date-picker-utils'
+import { toDayJs, fromDayJs, toServerWallClock, formatFilterDate, parseFilterDate } from './date-picker-utils'
 
 dayjs.extend(utc)
 dayjs.extend(timezone)
@@ -118,6 +118,34 @@ describe('formatFilterDate', () => {
   })
 })
 
+describe('parseFilterDate (read-back round-trip)', () => {
+  // Pins the regression: stored UTC ISO must not shift the picker day in browsers west of UTC.
+  const tsBrowserLocalMidnight = new Date(2026, 2, 15).getTime() / 1000
+
+  it('returns null for null', () => {
+    expect(parseFilterDate(null)).toBeNull()
+  })
+
+  it('round-trips a respect=false stored value back to the originally picked day', () => {
+    const stored = formatFilterDate(tsBrowserLocalMidnight, false)!
+    expect(stored).toBe('2026-03-15T00:00:00Z')
+    const recovered = parseFilterDate(stored)!
+    expect(dayjs.unix(recovered).format('YYYY-MM-DD')).toBe('2026-03-15')
+  })
+
+  it('round-trips a respect=true stored value back to the originally picked day', () => {
+    const stored = formatFilterDate(tsBrowserLocalMidnight, true)!
+    const recovered = parseFilterDate(stored)!
+    expect(dayjs.unix(recovered).format('YYYY-MM-DD')).toBe('2026-03-15')
+  })
+
+  it('ignores any offset or Z marker on the stored value (calendar day only)', () => {
+    expect(dayjs.unix(parseFilterDate('2026-03-15T00:00:00Z')!).format('YYYY-MM-DD')).toBe('2026-03-15')
+    expect(dayjs.unix(parseFilterDate('2026-03-15T00:00:00-04:00')!).format('YYYY-MM-DD')).toBe('2026-03-15')
+    expect(dayjs.unix(parseFilterDate('2026-03-15T00:00:00+09:00')!).format('YYYY-MM-DD')).toBe('2026-03-15')
+  })
+})
+
 describe('fromDayJs — unchanged save behaviour', () => {
   it('formats a dateString with the supplied output format', () => {
     expect(fromDayJs(dayjs('2024-01-15 13:30'), 'dateString', 'YYYY-MM-DD HH:mm')).toBe('2024-01-15 13:30')

assets/js/src/core/components/date-picker/utils/date-picker-utils.ts

@@ -60,6 +60,17 @@ export const formatFilterDate = (timestamp: number | null, respectTimezone: bool
   return `${dj.format('YYYY-MM-DD')}T00:00:00Z`
 }
 
+/**
+ * Inverse of `formatFilterDate`. Slices the calendar prefix so the read-back picker shows the
+ * picked day regardless of any offset / `Z` marker on the stored value.
+ */
+export const parseFilterDate = (dateStr: string | null): number | null => {
+  if (dateStr === null) {
+    return null
+  }
+  return dayjs(dateStr.slice(0, 10), 'YYYY-MM-DD').unix()
+}
+
 export const toDayJs = (value?: unknown, format?: string, options?: ToDayJsOptions): Dayjs | null => {
   if (dayjs.isDayjs(value)) {
     return value

assets/js/src/core/modules/element/dynamic-types/definitions/field-filters/components/dynamic-type-field-filter-date-component.tsx

@@ -9,15 +9,14 @@
  */
 
 import React from 'react'
-import dayjs from 'dayjs'
 import { Select } from '@Pimcore/components/select/select'
 import { Flex } from '@Pimcore/components/flex/flex'
 import { DatePicker } from '@Pimcore/components/date-picker/date-picker'
 import { DateRangePicker } from '@Pimcore/components/date-picker/date-range-picker'
 import { useDynamicFilter } from '@Pimcore/components/dynamic-filter/provider/use-dynamic-filter'
 import { t } from 'i18next'
 import { type AbstractFieldFilterDefinition } from '../dynamic-type-field-filter-abstract'
-import { formatFilterDate } from '@Pimcore/components/date-picker/utils/date-picker-utils'
+import { formatFilterDate, parseFilterDate } from '@Pimcore/components/date-picker/utils/date-picker-utils'
 import { isFieldRespectTimezone } from '../../objects/data-related/types/abstract/dynamic-type-object-data-abstract-date'
 
 export enum DatePickerSettingValue {
@@ -97,9 +96,7 @@ export const DynamicTypeFieldFilterDateComponent = (props: DynamicTypeFieldFilte
   }
 
   const convertISOToTimestamp = (dateStr: string | null): number | null => {
-    if (dateStr === null) return null
-
-    return dayjs(dateStr).startOf('day').unix()
+    return parseFilterDate(dateStr)
   }
 
   const handleDateChange = (field: 'on' | 'from' | 'to', value: string | null): void => {