1. finish working, call an end to the task
it's late, you should call it a day/night
The expression 'to call it a day' or 'call it a night' means to finish something or to stop for now. It is often used to bring long meetings or work to a close and to indicate that everyone needs to stop and resume at another time. "This meeting has gone on for much longer than anticipated, I think we should call it a night and talk again next week." "I was studying late yesterday, I didn't call it a day until well past 1 am." These are informal expressions but you will often hear them being used in professional situations too.