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Happy Leap Day on 29 February

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STATEWIDE–Thursday February 29 is a Leap Day, but have you ever wondered what it would be like if there were no leap years? That’s going to happen eventually.

“If you wait around two or three million years, your calendar is going to be a lot simpler. You won’t have leap days anymore. That’s when the number of days in a year will be exactly 365,” said David Minton, associate professor of planetary sciences in the Department of Earth, Atmospheric, and Planetary Sciences in Purdue University’s College of Science.

Minton says that is going to happen because the length of the day is getting longer due to tidal effects from the moon. That’s been happening steadily over Earth’s geologic history.

In the meantime, though, Minton says there has to be leap years.

“If we didn’t have leap years, what would happen is eventually the calendar would get out of sync with the seasons. We like to have the start of spring being in March. If we didn’t have leap years, eventually the start of spring would drift and we’d have spring in like January or October,” said Minton.

Minton says the solar system influences us “in ways we don’t full appreciate” because society is organized around timekeeping, which is completely tied to the movement of the planets.

The current system used is the Gregorian calendar. The Julian calendar, created by Julius Caesar, added a leap day every four years, but Minton says that was not quite right and the calendar would drift over centuries. The Gregorian calendar adds in some extra offsets. Every year divisible by four becomes a leap year, except for end-of-century years, which must be divisible by 400 in order to be a leap year. For example, a leap year was skipped in the year 1900, but 2000 was a leap year.