The Geek Stuff shows you how to setup Anacron on Linux

Anacron is the cron for desktops and laptops. Anacron does not expect the system to be running 24 x 7 like a server. When you want a background job to be executed automatically on a machine that is not running 24 x 7, you should use anacron.

For example, if you have a backup script scheduled everyday at 11 PM as a regular cron job, and if your laptop is not up at 11 PM, your backup job will not be executed. However, if you have the same job scheduled in anacron, you can be sure that it will be executed once the laptop come back up.

  Cron Vs Anacron: How to Setup Anacron on Linux (With an Example)