Tuesday
From UnAnything Wiki
Tuesday is the new Friday, because it is the day Thecomputernerd01 replaced Friday with in his parodies of songs about Friday. It is named for Tiw and is associated with Mars (the planet), probably because of interpretatio germanica or something.
It is the third day of the week, and anyone who says it is the second day of the week is WRONG, even if tehy are the International Organization for Standardization.