Guides
Dates and times
Where a time comes from and how it is shown.
An event has no timezone of its own. Times are entered in the browser's timezone and stored as instants; the API refuses a time without an offset. Pages show times in the reader's timezone. Emails cannot know it, so they print dates in UTC and say so. Editing a session and leaving a time as it was keeps the exact instant, even inside a repeated daylight-saving hour; a new time in a skipped hour is refused.