Not to be confused with traditional Sunday Fun days.
Or Festivus festivities.
Originally celebrated 2011 in Milwaukee WI this is a day in which all members of a particular social pond break from otherwise responsible life styles to enjoy a day of no cares worries or responsibilities. These days generally include mistaken time zone recognition as 5 O'clock is observed with breakfast lunch and dinner.
Twiderpation Day was so awesome I totally forgot I was in WI!!!