Mondaypause 

It is that day of the week when the weekend ends and you have to get up and go back to work.

I need another cup of coffee to get beyond my mondaypause

Mondaypause by Lyricalroger February 16, 2015

Mondopause 

The act of persistently having a bad attitude on mondays, kind of like menopause, but less dramatic.

Steve's mother has a bad case of mondopause.

Mondopause by FergyA October 5, 2010