Many actions you may want to take place instantly. But for some actions there are good reasons to perform them at a certain time or date, or to automatically repeat them at a specified time interval. For example:
- Publish a project's resources at a certain time when they should go "online".
- Clean up the image cache frequently
- Delete expired resources from time to time
The reason for executing a task scheduled for one-time execution may have two different reasons. Either the task's result should not appear before a certain date, or the task is resource intensive and should be performed at a time when your website is not visited too often, e.g., overnight.