Orthodox Christians celebrate Christmas on January 7. Their “old new year” is a week later, on January 14. It is all Julius Caesar’s fault …
The Romans sometimes neglected to introduce an extra month every two years to amortize the difference between their lunar calendar and the natural solar year. Julius Caesar decreed that the year 46 BC should have 445 days (some historians implausibly say: 443 days) in order to bridge the yawning discrepancy that accumulated over the preceding seven centuries. It was aptly titled the “Year of Confusion”.
To “reset” the calendar, Julius Caesar affixed the New Year on January 1 (the day the Senate traditionally convened) and added a day or two to a few months.
He thus gave rise to the Julian Calendar, a latter day rendition of the Aristarchus calendar from 239 BC. After his assassination, the month of Quintilis was renamed Julius (July) in his honor.
The Julian calendar estimated the length of the natural solar year (the time it takes for the earth to make one orbit of the sun) to be 365 days and 6 hours. Every fourth year the extra six hours were collected and...