How can I schedule a Task to execute at a specific time using celery?

Question

I've looked into PeriodicTask, but the examples only cover making it recur. I'm looking for something more like cron's ability to say "execute this task every Monday at 1 a.m."

Answer 1

Use

YourTask.apply_async(args=[some, args, here], eta=when)

And at the end of your task, reschedule it to the next time it should run.

Answer 2

How you can read in this tutorial, you can make a PeriodicTask, i think if you have execute a task at 1 .am. Monday's morning is because you wan to run a long cpu/mem operation, rememeber celery use ampq for enqueue tasks.

Answer 3

The recently released version 1.0.3 supports this now, thanks to Patrick Altman!

Example:

from celery.task.schedules import crontab
from celery.decorators import periodic_task

@periodic_task(run_every=crontab(hour=7, minute=30, day_of_week="mon"))
def every_monday_morning():
    print("This runs every Monday morning at 7:30a.m.")

See the changelog for more information:

http://celeryproject.org/docs/changelog.html

Answer 4

I have just submitted a patch to add a ScheduledTask to accomplish a small bit of time based scheduling versus period based:

http://github.com/paltman/celery/compare/scheduled-periodic-task