Airflow scheduled dags now working as expected

Question

I cannot understand how scheduler works, I created some dags with:

schedule_interval="0 21 * * *",
start_date=pendulum.datetime(2022, 5, 3, tz="UTC"),
catchup=False,
"max_active_runs": 1,

I activated the dag yesterday afternoon around 15.00 and I executed manually the dags to verify they works.
This morning I checked the dag execution and I saw the the dags have not been executed yesterday (2022-05-03 at 21.00) as expected (this is the next run date reported by airflow) why?
What am I wronging?
I am using airflow 2.2.4 Thanks

Answer 1

Manual runs start as soon as you trigger it. Scheduled runs are subject to Airflow scheduling mechanisem. I explained it in Problem with start date and scheduled date in Apache Airflow

In your case start date of 2022-05-03 with interval of 0 21 * * * means that the first run will start on 2022-05-04 21:00. The execution_date of this run will be 2022-05-03 21:00. So if you wanted the first run to start on 2022-05-03 21:00 you need to set:

start_date=pendulum.datetime(2022, 5, 2, tz="UTC"),
schedule_interval="0 21 * * *",

Alternatively, if you want to specify exact run times you will need to use Timetables then you can customize DAG Scheduling with Timetables.