Throwback Thursday: The Story Behind the Modern Calendar

The first day of the new year falls on a Thursday every six to 11 years. The next year that January 1st falls on a Thursday will be 2032. But for now, we thought it may be fun to share how
our modern calendar year came to be. Every morning, we check the date without thinking twice.

The calendar we live by, the months, weeks, and even weekends, is the result of thousands of years of human observation, power, and compromise. Who decided all this?

Before calendars hung on kitchen walls, ancient civilizations looked to the skies. Early calendars were based on the moon, which takes about 29 and a half days to complete a cycle. Twelve lunar months add up to about 354 days, short of the sun’s solar year. The mismatch caused
seasons to drift and farmers quickly noticed when planting times stopped making sense.

But the ancient Romans tried to remedy this. Their first calendar had just 10 months, beginning in March, named for Mars, the god of war. That’s why September, October, November, and December still carry names meaning seven, eight, nine, and 10. But January and February were
added later, bringing 12 months into the fold and matching the sun’s year.

Then, in 45 B.C., Emperor Julius Caesar introduced his Julian calendar, based on the sun instead of the moon. It had 365 days and a leap year every four years. For the most part, it works. But it was off by about 11 minutes per year, and that adds up over centuries. So in 1582, Pope Gregory XIII corrected that with his new Gregorian calendar. It’s the system most of the world uses now.

The seven-day week started in ancient Babylon, when astronomers tracked seven visible celestial bodies – the sun, moon, and five planets, with each day dedicated to one. A few of those names still shape our lives today – ‘Sun’day, ‘Mon’day, and ‘Saturn’-day.

As our modern civilizations developed into the ages of math and science, time was measured by the land and labor tied to it. Settlers planned lives around planting seasons, harvest months, daylight, livestock cycles, tobacco cutting, all following the solar year before anyone talked about fiscal quarters or school semesters.

Adopting standard calendars and time zones helped connect communities through railroads, mail routes, interstate commerce, and more. Institutions reflect that rhythm today. While the calendar was shaped by emperors, popes, and astronomers, its meaning has always been local, living in harvests, holidays, and school bells.