CLEVELAND — Certain things get repeated so often that people start to believe they're true, even if they haven't checked the facts themselves.
THE CLAIM
For example, you’re probably familiar with this claim: "Leap Year happens every four years."
THE SOURCES
This is a claim that I've personally been hearing my whole life, so to VERIFY if that's true, we checked with these sources:
- The Smithsonian National Air and Space Museum in Washington, D.C.
- Associate Professor of History at Case Western Reserve University Aviva Rothman
THE RESEARCH
First, the National Air and Space Museum explains that the point of leap year (which is when we add an extra day to the calendar at the end of February) is to keep our calendars synced up with the seasons. This way, the weather gets cold during the months when we're used to it being cold and gets warm during the months when we're used to it being warm.
But over time, even adding an extra day every four years isn't quite enough to keep our weather on that track. Associate Professor of History at Case Western Reserve University Aviva Rothman explains why:
"The time it takes for the earth to go around the sun is 365.242 days. So if [we] want to keep with that, 365 days is really close. Even adding the leap day is even closer, but if you add a lot of time over hundreds of years, you're going to end up slipping. Even with the leap day every four years, we're getting ahead by three days or so every 400 years."
That might not sound like a big deal in the short term, but over hundreds of years that, would mean our summers, which we're used to experiencing in June, would start in December.
Because of that, as the National Air and Space Museum explains, "Not every four years is a Leap Year. The rule is that if the year is divisible by 100 and not divisible by 400, Leap Year is skipped."
To say that a different way: In years that end in an even hundred number like 2000, 2100, and 2200, which are all evenly divisible by four and 100, if you can't also evenly divide the year by 400, it’s not a leap year. That's why 2000 was a leap year, but 2100 and 2200 won't be.
THE ANSWER
So we can VERIFY the claim that leap year happens every four years is false.
If you have a claim or question you'd like verified, please email it to verify@wkyc.com or text it to 216-344-3300.