Could someone try and give me a hand on how to do this?

I want to run a script after 5 minutes, every 5 minutes. From what I've been able to search for it seems I can use 'retutime' for the task but I'm not quite sure how to set it up.

I'm guessing i'll need to run a script that includes the retutime command which also calls that script again.

Any ideas? Please help!