weekend fucker
Noun.

A person who ruins weekends. Namely by requiring others to attend meetings, do work, or finish projects over the weekend because of their incompetence, inefficient planning, and/or laziness.

Frequently occurs in college dorms and office settings.
I had to go in on a Saturday because that new guy didn't finish the paperwork on time! Weekend fucker.

Those weekend fuckers waited until Sunday to email me that they would not be finishing their half of the lab report due Monday afternoon.