I vehemently disagree, you can't just redefine Pi-Day to what you want. Pi Day is 3/14, not 4/4 or 6/6.
As for calling it Doomsday, well, it's from the title of the paper about the algorithm, by the man who invented it, the famous John Conway: https://en.wikipedia.org/wiki/Doomsday_rule
As for calling it Doomsday, well, it's from the title of the paper about the algorithm, by the man who invented it, the famous John Conway: https://en.wikipedia.org/wiki/Doomsday_rule