Could be a global affair
Pine-Boxing Day (Commonwealth countries)
In-The-Deep-Endce Day (Mostly the USA even though a lot of countries have independence days)
Sad-turnalia (Pagans)
Hubristmas and Seaster (Christian world)
Pall(bearer)entine's Day (Worldwide, I guess)
Sinkran (Thailand)
Holi Diver (India)
Corpse-us Cristi
Sinko de Mayo (Mexico)
The would be American single issue political assassin would be for something much dumber than a cult.
Some guy is going to assassinate Bill Clinton because they want the legal drinking age to be lowered to 18