Happy leap day! I learned today that in the Julian calendar, feb 23 was the leap day. The bis sextum, or "double sixth" was the sixth day before the Kalends (first of the month) of March. Thus, six days before March 1 is feb 23. On leap years this day was doubled. So there were two Feb 23ds. At least it's not like the Jewish calendar where every so often they add a leap month.
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