## Symptom
Creating or updating an Opportunity on a board view crashes with:
```
Uncaught TypeError: e.split is not a function
at splitDateString (date-fns) → parseISO → isMatchingDateFilter
→ isRecordMatchingFilter → <group-by optimistic effect> → createOneRecord
```
`e` is a non-string (a `Date` object, shown as `{}` in the debugger).
Distinct from the `null` case fixed in #22029.
## Root cause
Reproduced on a live board filtered by **Close date — Is relative —
"This quarter"** (a `DATE_TIME` field).
When you create a record in a filtered view, `useCreateNewIndexRecord`
derives default field values from the view's filters via
`buildRecordInputFromFilter` → `buildValueFromFilter`. For a date field,
`computeValueFromFilterDate` returned a JS **`Date` object** (`new
Date()` / `new Date(value)`), assigned to the new record verbatim. The
optimistic record's `closeDate` was then a `Date`, not an ISO string,
and the group-by optimistic effect matched it via `parseISO(dateObject)`
→ `dateString.split is not a function`, crashing every create/update in
the view.
## Fix
`computeValueFromFilterDate` now returns timezone-aware **ISO strings**
via Temporal, mirroring what `turnRecordFilterIntoGqlOperationFilter`
produces for the same filters — so a record created in a date-filtered
view actually satisfies its own filter:
- **`DATE_TIME`** → an instant. Date-only filter values (a `DATE_TIME`
"is" filter stores `yyyy-MM-dd`, no time) are resolved to the start of
day in the user's time zone, matching how the filter operands are built
— `Temporal.Instant.from()` alone would `RangeError` on them.
- **`DATE`** → a plain date `yyyy-MM-dd` resolved in the **user's time
zone** (`Temporal.Now.plainDateISO(timeZone)`). A bare `new
Date().toISOString()` would use the UTC date, which near midnight is the
wrong calendar day for non-UTC users, so the new record could miss its
own `IS_TODAY`/relative filter. The time zone is threaded from
`useUserTimezone` (same source the filter side uses).
- `IS_BEFORE` subtracts 1 day for `DATE` / 1 minute for `DATE_TIME` (the
`-1 minute` special-case moved out of `buildRecordInputFromFilter`,
which now just assigns the string).
No `Date` object ever reaches `parseISO`, and the value matches the
filter operand, so the optimistic card lands in the right place.
## Tests
- `buildValueFromFilter.spec.ts`: every date operator returns an ISO
**string** (round-tripped to the expected instant); a `DATE` block
asserts date-only `yyyy-MM-dd` output and that `IS_TODAY` resolves to
the correct calendar day **per time zone** at a UTC day boundary
(`2024-03-20` UTC vs `2024-03-21` Asia/Tokyo); a date-only `DATE_TIME`
`IS` value resolves to start-of-day in the user time zone (UTC vs
America/New_York) without throwing.
- `buildRecordInputFromFilter.test.ts`: filter-derived date values are
ISO strings, not `Date` objects.
## Verified locally (Chrome)
Reproduced the exact prod scenario on the **By Stage Opportunities
Kanban board** (the group-by optimistic effect) with a **Close date — Is
relative** filter:
- Created a card in a column → **no `split is not a function` crash**;
the card got a valid Close date (`now` for the relative filter, e.g. `25
Jun 2026 13:10`). Console clean.
- Also verified a **table view + Close date — Is** filter: created
record gets a valid start-of-day value (`25 Jun 2026 00:00`).
Both `IS_RELATIVE` (→ now instant) and the date-only `IS` (→
start-of-day in the user tz) paths produce string values that the
optimistic matcher handles without throwing.
Charles Bochet
d8cb4aa15b