Timezone Confusion Causes Unexpected Scheduling

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configurationUpdated Jan 24, 2026

DAGs run at unexpected times or miss scheduled windows due to implicit UTC vs. local timezone handling, leading to data freshness issues and business impact.

Sources

7 Common Errors to Check When Debugging Airflow DAGswww.astronomer.io

How to Fix 'DAG Scheduling' Airflow Issues - OneUptimeoneuptime.com

Technologies:

Apache AirflowThe root cause of this issue originates in Apache Airflow

airflow.dagrun.schedule_delay

airflow.dagrun.first_task_scheduling_delay

How to detect:

Check for DAG runs occurring at times that don't match expected schedule in local timezone. Monitor execution_date vs. actual start time discrepancies. Review logs for timezone-related warnings.

Recommended action:

Set explicit timezone in DAG definition using pendulum.datetime(tz='...'); configure default_timezone in airflow.cfg; use CronTriggerTimetable with explicit timezone for cron expressions; validate schedule_interval produces expected execution times in target timezone.