@ShadowWizardWearingMask "Decennial" is a relatively common term in the English language
Also, I use the word "K-Day", which fewer people know, but provided a dictionary link in my bio.
By the way, for a while, vehicle number plates in the U.S. state of California all had the word "sesquicentennial" printed on them (150th anniversary of California graduating from colonial territory to state, i.e. part of sovereign territory).
