To enable the tasks, open your project on the Control Panel and select Cron Jobs from the menu. Next enter the command and select the period, in which the repeating task should be run.
For example, if you select every 10 minutes, the task will be run every hour at :10, :20, :30, :40, :50 and :00.
A command could be something simple like:
python manage.py sync_my_db