Timed power off

[Csaba Petran]

Hello! How can I schedule power off the board? After power on, I want to turn off the device automatically 7 hours later. 
At the moment, time switches turn off the boards power supply in every day... dead 3 SD cards...

[NicoD]

4 minutes ago, Csaba Petran said:

Hello! How can I schedule power off the board? After power on, I want to turn off the device automatically 7 hours later. 

https://www.computerhope.com/unix/ushutdow.htm