This upcoming Monday, you get the excuse to have the case of the Mondays even though it's Martin Luther King Jr. Day, because according to People magazine, Monday is also Blue Monday which is the Most Depressing Day Of The Year.
What is a Blue Monday? It "is the most depressing date on the calendar, according a strange tradition with even more unusual origins."
According to the BBC and Dr. Cliff Arnall who coined "Blue Monday" is has to do with a lot of things - weather, average debt, "the time that’s elapsed since Christmas, people’s average levels of motivation, having to return to work, and how long it took people to break their New Year’s Resolutions."
So you can either sulk in it or just pretend it doesn't exist but could be a good day to let all things pent up go away maybe by just talking to someone, handling business or even trying to just let it go!