Firefighters have interesting working rules. They are expected to work 8 hour days, but they are in the fire house for multi-day shifts.

Their work 8 hours which is a mix of physical fitness training (carefully designed to keep them in shape without being too wore out to respond if something does happen as they finish training) and training. They have a lot of time to learn about all the latest medical emergency treatments, the latest in fire fighting. They get constant CPR refreshers because even though they are often first on the scene when CPR is needed it still doesn't happen often enough to remember.

The other 16 hours - 8 of them are sleeping. the other 8 are theirs to do whatever. Any good firehouse will keep plenty of games (TV, board games, pickelball...) so that they are not bored.