On Wed, 18 May 2022 at 17:18, Ash Berlin-Taylor <a...@apache.org> wrote: > Start date also makes sense for a cron-based dag with catch-up too though...
True. So, 1. A timedelta without a `start_date` is not wrong, but it'll use midnight as the reference time (I think this is better than "date first added" because that could be 12:34:56 or some other random deployment time). 2. If you need another reference time, for example daily at 4pm, use a cron-based timetable (which we're also likely to extend soonish to allow composability, i.e. AND, OR, NOT). 3. Catch-up fills in missing DAG runs starting with `start_date` or (if unset) the earliest scheduled/automated DAG run, i.e. the effective `start_date`.
