antigravity-skills-reference/skills/dbos-python/references/pattern-scheduled.md

title, impact, impactDescription, tags

title	impact	impactDescription	tags
Create Scheduled Workflows	MEDIUM	Run workflows exactly once per time interval	scheduled, cron, recurring, timer

Create Scheduled Workflows

Use @DBOS.scheduled to run workflows on a schedule. Workflows run exactly once per interval.

Incorrect (manual scheduling):

# Don't use external cron or manual timers
import schedule
schedule.every(1).minute.do(my_task)

Correct (DBOS scheduled workflow):

@DBOS.scheduled("* * * * *")  # Every minute
@DBOS.workflow()
def run_every_minute(scheduled_time, actual_time):
    print(f"Running at {scheduled_time}")
    do_maintenance_task()

@DBOS.scheduled("0 */6 * * *")  # Every 6 hours
@DBOS.workflow()
def periodic_cleanup(scheduled_time, actual_time):
    cleanup_old_records()

Scheduled workflow requirements:

• Must have @DBOS.scheduled decorator with crontab syntax
• Must accept two arguments: scheduled_time and actual_time (both datetime)
• Main thread must stay alive for scheduled workflows

For apps with only scheduled workflows (no HTTP server):

import threading

if __name__ == "__main__":
    DBOS.launch()
    threading.Event().wait()  # Block forever

Crontab format: minute hour day month weekday

• * * * * * = every minute
• 0 * * * * = every hour
• 0 0 * * * = daily at midnight
• 0 0 * * 0 = weekly on Sunday

Reference: Scheduled Workflows