Confirmed elapsed-time error across DST
Reviewed master at 886c36d8ebe861aa987059a1744d45b78797baae (v4.7.0). Suggested priority: P2.
parse_time adds a timedelta directly to a datetime carrying the configured ZoneInfo timezone. Across a daylight-saving transition this is wall-clock arithmetic, not the requested elapsed duration.
Reproduction
now = datetime(2026, 3, 7, 12, 0, tzinfo=ZoneInfo("America/New_York"))
result = datetime.fromisoformat(parse_time("in 24 hours", now=now))
elapsed = (result.astimezone(UTC) - now.astimezone(UTC)).total_seconds()result: 2026-03-08T12:00:00-04:00
elapsed_seconds: 82800 (23 hours)
expected_seconds: 86400 (24 hours)
Independently reproduced twice. Users in a DST-observing configured timezone can get a reminder or operation an hour early/late.
Acceptance criteria
- Use elapsed-time arithmetic for seconds/minutes/hours, converting through UTC if needed before serializing in the configured timezone.
- Test spring-forward and fall-back transitions by comparing UTC instants, not same-zone datetime subtraction.
- Preserve calendar/wall-clock semantics for
tomorrow at ... and cron.
- Explicitly decide day/week wording separately rather than accidentally changing calendar expectations.
Behavior change: elapsed-duration requests around offset transitions become accurate. This is not a request to change cron timezone semantics. No source changes were made.
Confirmed elapsed-time error across DST
Reviewed
masterat886c36d8ebe861aa987059a1744d45b78797baae(v4.7.0). Suggested priority: P2.parse_timeadds a timedelta directly to a datetime carrying the configured ZoneInfo timezone. Across a daylight-saving transition this is wall-clock arithmetic, not the requested elapsed duration.Reproduction
Independently reproduced twice. Users in a DST-observing configured timezone can get a reminder or operation an hour early/late.
Acceptance criteria
tomorrow at ...and cron.Behavior change: elapsed-duration requests around offset transitions become accurate. This is not a request to change cron timezone semantics. No source changes were made.