Dates and time
Why every entry sits on the local day the person saw, and how OWLF flags guesses.
An entry belongs to the calendar day the person saw in the app. Producers never derive that day from a UTC timestamp: an entry written at 23:30 in Berlin stays on that day, even though it is the next day in UTC.
| Field | When |
|---|---|
date + time |
Always. Local day and wall-clock time; time is null when unknown. |
instant |
The file stores an absolute moment: epoch or offset. RFC 3339 with seconds and offset: 2026-03-01T21:40:00+01:00. |
zoneless |
instant comes from a bare epoch, so date and time are a guess in the converting device’s zone. Consumers re-derive the day in the person’s zone. |
utcDate |
The file prints a UTC day next to a local time. Consumers re-derive the day in the person’s zone. |
instant wins over date + time for ordering. A consumer that knows the person’s time zone should use it to re-derive the day whenever zoneless or utcDate is set.