“A case of the Mondays”—Monday is often the first day of the school/work week—is a saying that has been printed on many images. “A case of the Mondays was said three times in the film comedy Office Space (1999), written and directed by Mike Judge.
 
The Monday saying did exist before the 1999 movie, although it was rare. “Got a case of the Miserable Mondays? Chase them away with Feminique—every Monday morning the the Tribune!” was printed in the Chicago (IL) Tribune on December 9, 1971. “The pastry shop is my favorite. If I (Robert Gilson—ed.) have a case of ‘the Mondays,’ I can always find refuge there” was printed in The Sunday Star-Ledger (Newark, NJ) on December 12, 1982.
   
   
Wikiquote: Office Space   
Office Space is a 1999 comedy film that pokes fun at work life in a typical software company during the late 1990s by portraying individuals who are completely fed up with their jobs.
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Peter Gibbons: Let me ask you something. When you come in on Monday and you’re not feeling real well, does anyone ever say to you, “Sounds like someone has a case of the Mondays?”
Lawrence: No. No, man. Shit, no, man. I believe you’d get your ass kicked sayin’ something like that, man.
       
9 December 1971, Chicago (IL) Tribune, sec. 1, pg. 16, col. 1L
Got a case of the Miserable Mondays? Chase them away with Feminique—every Monday morning the the Tribune!
 
12 December 1982, The Sunday Star-Ledger (Newark, NJ), “Young chef has Senate ‘eating out of his hand’” by Bob Rastelli, Accent sec., pg. 6, col. 3:
“The pastry shop is my favorite. If I (Robert Gilson—ed.) have a case of ‘the Mondays,’ I can always find refuge there.”
 
IMDb (The Internet Movie Database)
Office Space (1999)
Quotes
Peter Gibbons: Let me ask you something. When you come in on Monday and you’re not feeling real well, does anyone ever say to you, “Sounds like someone has a case of the Mondays?”
Lawrence: No. No, man. Shit, no, man. I believe you’d get your ass kicked sayin’ something like that, man.
 
Urban Dictionary
case of the monday’s
symptoms of a useless or horrible Monday morning after returning from the weekend, used in the movie Office Space
Sounds like a case of the monday’s
by alpine January 25, 2004
   
Urban Dictionary
Case of the Mondays
A phrase used to describe someone that has a bad mood when he or she comes to work or school on Mondays.
OR
A phrase that someone uses if he or she wants to get their ass kicked by their fellow co-workers or school mates.
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by Elmer November 24, 2005
     
YouTube
Case of the mondays
Pekkaaa
Published on Apr 8, 2010
no, man.
   
Google Books
Your Church in Rhythm:
The Forgotten Dimensions of Seasons and Cycles
By Bruce B. Miller
San Francisco, CA: Jossey-Bass
2011
Pg. 109:
Monday is usually a tough day back at the job, which is why people say, “I’ve got a case of the Mondays.”
 
YouTube
Office Space (2/5) Movie CLIP - Bad Case of the Mondays (1999) HD
Movieclips
Published on Aug 11, 2015
Office Space movie clips: http://j.mp/1MQtme3
(“A case of the Mondays” is said twice, starting first at 1:20.—ed.)
 
Google Books
Title A Case of the Mondays: An Adult Coloring Book for Your Unmotivated Side
Author Carla Schauer
Publisher Amazon Digital Services LLC - Kdp Print Us, 2016
ISBN 0692657312, 9780692657317
Length 52 pages
   
Twitter
Emily misses Alex 🥺💛
@Emily_47616
I’m having a case of the mondays but it’s Tuesday 😐
6:31 PM · Jul 23, 2019·Twitter for iPhone