Weekends go too quickly. Turn around and it's Sunday night and you're facing "The Sunday Evening Blues." Dread is the flavor of the moment, spoiling any time you've got left. You become cranky. You want to make it last so you don't do anything to get distracted so that the time passes slower which cheats you out of starting anything fun and you wind up staying up later than you should trying to stretch it out which starts Monday off even worse.
A legion of sleep deprived ticked off zombies longing for Friday when they can do it all again.