Possible to know what time vehicle turns ignition on or off?

Hello,

I want to know if there is a way we can know the time when a vehicle turns their ignition on or off.

It does not really have to be vehicle, but just simply any device. I do not mean unit going online or offline.
But let's say if the unit presses a button in their device, it will trigger an on/off thing and leave time when it did that?

I hope my English is not confusing you.