have (got) a case of the Mondays

To have a persistent feeling of sluggishness, laziness, apathy, or crankiness because it is Monday (typically the first day of the week for work or school). The phrase was popularized by the 1999 film Office Space. A: "Sorry, I just can't seem to get anything done this morning." B: "Sounds like someone's got a case of the Mondays!" Man, I've barely made any progress on this report. I really have a case of the Mondays this week. All three of them are going to be late to work? So they all have a case of the Mondays, huh? I didn't know it was contagious.