Bissextus

In some cultures there was the tradition that on the 29th of February women were “allowed” to propose marriage to a man and he could not refuse (think Sadie Hawkins). I could have flown out there today and snagged me a husband. Heehee!

bissextile (adjective) Definition: "(1) referring to a leap year or (2) the extra day in a leap year." The extra day is referred to as "bissext," or "bissextus."

Etymology: This word comes from Latin bissextilis "having an intercalary day" from the first word of the phrase bis sextus (dies) "twice the sixth day," from bis "twice" and sextus "sixth." The phrase arises from the fact that the sixth day before the Calends of March (February 24} occurred twice every leap year in the Roman calendar. Thus this "sex" comes from the Latin word for "six," which shares the same origin as German "sechs," Dutch "zes," Spanish "seis," French "six," Italian "sei," Russian "shest'."

–Dr. Language, YourDictionary.com

I did warn y’all that I’m fascinated by etymology, didn’t I? Go ahead, call me a Word Nerd, I don’t mind.