What do tower controllers do when the airport is quiet? Listening Hayward Executive Tower on LiveATC in the night, I noticed ATC can be quiet for periods of more than 30 minutes, and sometimes the communication is not even with an aircraft, but with a maintenance car.

What do ATC operators when the airport is quiet?
The same things people do when working jobs like night shift guard shack operator... catch up on paperwork, read, study, listen to music, etc.