Screentime activated while MacBook is off?

I noticed that although my Macbook (M2) is turned off at night, Screentime tells a different story. According to his numbers I was running Finder from 00.00-08.00, but like I said: the laptop was turned off. The laptop wasn't connected to a charger nor updating its software. What could be the reason for this? And more importantly: how can I get a more accurate number in Screentime?