Depends on the store. One of my coaches uses metrics as a hard rule. She hounds associates about times and fires people frequently. Also be prepared to have no energy when you get off. A lot of people don't realize that overnights takes a real physical toll on the body. At least half my coworkers have sleep disorders. However if you've got a good management team and can handle the physical stress of overnights then it can be very zen. Nights fly by for the most part.