Sundayitis 

That point on a Sunday afternoon where you remember you have work or school tomorrow - which ruins the rest of your weekend.

Me: "What's wrong, you look down..."
You: "I just remembered I have work tomorrow."
Me: "You've got Sundayitis bad."

Sundayitis by parhwy December 16, 2012

Sundaynitis

A feeling/condition of impending agony and dread; associated with the upcoming work week. Brought on by the P.M. hours of Sunday night and the conclusion of the weekend.

Bradley-Dave: "Why won't you come out to the movie with us, Jenny-Lynn?"
Jenny-Lynn: "Golly, I don't know, Bradley-Dave. I don't think I can. My math test is tomorrow, and I'm feeling Sundaynitis coming on."

Sundaynitis by Jenny/Bradley January 8, 2009

Sunnyitis 

(noun) pronounced: sun-ee-aye-tis To call in sick at work because the weather is nice out.

Oh, look's like she's calling in a case of sunnyitis again.

Sunnyitis by dalildevil August 10, 2016