Most of my shifts are from 5pm to 8am. (yep, 15 hours!)
Most times, I stop the boredom by:
Coming on forums.
Practising magic.
Making balloon models.
Playing computer games.
Reading.
Writing and rewriting scripts or just brainstorming ideas for shows.
I have spent hours deciding on which props I want to use, which may suit and keep for future, or which I just will never use.
Lastly, sometimes I do some work, though only about an hour or two max, most nights.