Well, they're all set-ups, so I think it's more for the fun of getting fired and getting paid for it.
The owner's are in on the gag, but the boss and co-workers aren't.
The new "employees" have to last as close to 3pm.
This one guy working in a ski shop has me cracking up here. He's wearing socks on his hands and has tried on and tested just about every piece of equipment in the store.
Hmmm... I'm betting that the "disrobing at 2:59" gambit wins.