January 1, 45BC Happy New Year

From the 7th century BC, the Roman calendar attempted to follow the cycles of the moon. The method frequently fell out of phase with the change of seasons, requiring the random addition of days. The Pontifices, the Roman body charged with overseeing the calendar, made matters worse. They were known to add days to extend political terms, and to interfere with elections. Military campaigns were won or lost due to confusion over dates. By the time of Julius Caesar, things needed to change.

When Caesar went to Egypt in 48BC, he was impressed with the way the Egyptians handled their calendar. Caesar hired the Alexandrian astronomer Sosigenes to help straighten things out. The astronomer calculated that a proper year was 365¼ days, which more accurately tracked the solar, and not the lunar year. “Do like the Egyptians”, he might have said, the new “Julian” calendar going into effect in 46BC…