Hi, I’m not part of the Airflow team but I came to the same conclusion, that the behavior is the opposite of what the documentation specifies. When using the cron notation then DST is properly honored, when using timedelta it is not. I played around with the DAG.following_schedule method to satisfy this was the case.
I’ve had production instance of airflow based on this that successfully respected the March/April DST changes in many timezones. Regards Damian From: Jiahao Chen [mailto:[email protected]] Sent: Monday, May 13, 2019 2:08 PM To: [email protected] Subject: Cron schedule with DST-aware timezone Hi team, I have a question about the expected behavior of Airflow scheduler when the schedule_interval is a cron expression and the start_date is in a timezone with DST. Based on the Airflow documentation https://airflow.apache.org/timezone.html#cron-schedules, the DST change will be ignored if schedule_interval is a cron expresion (e.g. '0 17 * * *'). And it gives an example that the GMT offset will not change regardless how DST changes. If I'm understanding it correctly, that means if I upload a DAG with a schedule_interval of "0 17 * * *" and a start_date of 2019-03-15 17:00 PST(GMT-8) which is before the DST change on March 10, the Airflow scheduler will always start the DAG on 5 pm everyday GMT-8 even after the DST change on March 10. However, that is not the behavior I've seen with my experimental code (see attachments). It looks like the the Airflow is actually taking the DST into account, since the execution time is always 17:00 locally, which is 1 hour off on the GMT after the DST change. Could you please confirm the behavior of Airflow scheduler in this use case? Thank you! Jiahao =============================================================================== Please access the attached hyperlink for an important electronic communications disclaimer: http://www.credit-suisse.com/legal/en/disclaimer_email_ib.html ===============================================================================
