fix(web): keep event's own date selectable in recurrence "Ends on" picker

[posthog]

Summary

• Who's hurt: users setting up a recurring timed event that runs past local midnight can't pick the event's own date as the recurrence end — it renders disabled (aria-label="Not available …"), a silent dead end with no visible explanation.
• Mechanism: RecurrenceSectionView derived the picker's minDate from the event's end. When an event ends at/after local midnight (e.g. 23:00–00:30, or anything ending 00:00 the next day), the end lands on the next calendar day. react-datepicker (v4.25.0) disables day cells by calendar day (differenceInCalendarDays), so the event's own start date — the date the user sees and reaches for — sorts before minDate and is disabled.
• Fix: anchor minDate to the event's start date, normalized to a bare YYYY-MM-DD. The recurrence can't stop before its own first occurrence, so the start date is the correct floor. Selecting it still produces a valid recurrence that includes the first occurrence (verified against CompassEventRRule expansion).

Note

The inbox report proposed a different mechanism (a timed minDate keeping its time of day, disabling the same-day cell). That does not reproduce on the pinned react-datepicker@4.25.0: it compares by calendar day and ignores time-of-day, so a same-day event's date is already selectable. The real trigger is the end date landing on a later calendar day than the start — which matches the report's captured DOM exactly (Not available Monday, August 3rd, 2026, i.e. that user's event ended on Aug 4). The report's suggested date-only normalization would have been a no-op.

Simplicity

• One-line change to how the floor is computed; the branch on event kind collapses since both kinds now use the same date-only start bound.

Automated validation

• Reproduced the exact symptom in a test (past-midnight event → Not available Monday, August 3rd, 2026); confirmed it fails on the old end-based bound and passes after the fix.
• Verified across timezones (UTC, America/New_York, Asia/Tokyo, …) that a normal same-day event was never disabled, and that a past-midnight event's start date flips from disabled → selectable.
• Confirmed via CompassEventRRule.all(...) that selecting the start date as UNTIL still yields the first occurrence — no empty-recurrence side effect.

Independent review

• No competing PR/issue found for this picker (gh pr list/gh issue list by wording and by path). Note: the report's other signal — GridContextMenuWrapper throw — is out of scope here and already handled by fix(web): stop throwing when right-clicking an uncached event #2549.

Test plan

TZ=Etc/UTC bun test src/views/Forms/EventForm/DateControlsSection/RecurrenceSection/

• 24 pass / 0 fail. biome check clean on the changed files; type-check clean.

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Created with PostHog Desktop from this inbox report.