Sundays are worse than Mondays
In my opinion, Sundays after 6pm are atrocious. The anxiety starts to kick in knowing you have to wake up for work/school in less than 10 hours, and the sun isn't even down yet. 10pm hits and you have to go to bed, but you can't sleep because of all that anxiety. Mondays at least go by very quickly and are tolerable, despite it being the beginning of the week.