DEVELOPER DOCUMENTATION / API v1
Dates and time
Distinguish Europe/London planning wall time from UTC metadata and handle offsets and daylight-saving transitions correctly.
London planning wall time #
Planning fields represent the local planning clock in Europe/London. Output has no offset. Do not label these values as UTC or automatically reinterpret them in the worker machine’s local timezone.
This includes task startedAt, completedAt, earliestStart, releaseDate; factual actualIntervals start/end; project targetDate and hardDeadline; and Incoming suggestedStart and plannedStart. Optional/unknown values can be null.
{"plannedStart":"2026-07-15T13:00:00"}Input with and without offsets
Planning inputs require an ISO date/time containing T and seconds, with optional up to seven fractional digits. A bare value is London wall time. A Z or explicit-offset value is an instant converted to London before planning persistence.
| Input | London planning value |
|---|---|
2026-01-15T12:00:00Z | 2026-01-15T12:00:00 · GMT |
2026-07-15T12:00:00Z | 2026-07-15T13:00:00 · BST |
2026-07-15T14:00:00+02:00 | 2026-07-15T13:00:00 |
Daylight-saving boundaries
A nonexistent bare spring wall time is rejected. For example, 2026-03-29T01:30:00 does not exist in London. The instant 2026-03-29T01:00:00Z converts to London 2026-03-29T02:00:00.
An ambiguous bare autumn time remains a wall-time value without selecting an instant. Both 2026-10-25T00:30:00Z and 2026-10-25T01:30:00Z convert to London 2026-10-25T01:30:00. API v1 retains this wall-time planning model; it does not preserve an offset to distinguish those two instants.
UTC metadata
Fields ending Utc represent instants and serialize with Z. Examples are notes/assistance createdUtc, claim expiresUtc, release releasedUtc, Incoming requestedAtUtc/actualStartUtc, respondedAtUtc, source lastSuccessUtc, events occurredUtc/receivedUtc/acknowledgedUtc and activation activatedUtc.
{"released":true,"releasedUtc":"2026-10-19T09:10:00Z"}Compare lease expiry using a UTC instant type such as DateTimeOffset. Preserve planning wall-time meaning separately. “All dates are UTC” is incorrect for this API. Actual start/effort remains unknown when no factual value was recorded.
See claim expiry, factual intervals and Incoming planning.