Turn on a device for x minutes and turn of for Y minutes and repeat

How do you acheive that you want to turn on a socket for X minutes and then off for Y minutes?
Like on for 10 minutes and off for 40 minutes, and then repeat for infinity

Use a timer app like chronograph.

Great! Will try that. Thanks!

This is my latest solution using cronjob and chronograph.
Sorry the flow is in German.

Sounds like a job for the loops app