Three separate defects all showed up as "I saved a schedule and it moved".
1. expandSchedule emitted two different wire formats. A one-off returned
start_time untouched - a naive wall-clock string, which the browser parses
in its own zone - while a recurring instance returned cursor.toISOString(),
an absolute instant derived by reading that same string in the SERVER's
zone. The browser converted it back and the two conversions do not cancel:
an operator in Tokyo saving Wednesday 20:00 got Thursday 10:00 from a
US-Central server. Only recurring schedules were affected, which is why it
looked intermittent.
The calendar was also the odd one out. services/scheduler.js compares
start_time as a string and never builds a Date from it, so expandSchedule
was the only place in the codebase treating a wall-clock time as an
instant - the drawing disagreed with playback as well as with the browser.
2. Saving an edit moved the schedule to today. The save handler rebuilds
start_time from `pendingCreateDate || new Date()`, and editSchedule()
restored only HH:MM - it never recorded the date being edited. Changing a
colour on a block dated 5 Aug rewrote it to this week. No timezone
mismatch required; this one hit everybody and silently altered stored data.
3. A cancelled drag-create leaked its date into the next schedule.
pendingCreateDate was cleared only on a successful save, and the modal's
two dismissers are inline onclick="...display='none'" attributes that
cannot reach that scope. The date is now assigned by every path that OPENS
the modal, so no dismissal path can leave a stale value behind.
Tests assert the property rather than a literal: that the wire value is
wall-clock and that the day survives a server/browser zone mismatch in BOTH
directions. A literal-string assertion would pass just as happily with the
bug present on a differently-configured CI box. Both new files fail on the
parent commit and pass here; the schedule, calendar and timezone suites are
green at 85 tests.
Claude-Session: https://claude.ai/code/session_014kfhrUPit5MCqxeTQyqr56
Co-authored-by: Dan Walters <dan.walters@bytetinker.net>
Co-authored-by: Claude Opus 5 <noreply@anthropic.com>
