UC Merced professor explains cause of Leap Year

MERCED, Calif. (KFSN) -- You may notice an extra day on the calendar this week.

That's because 2024 is a leap year.

February 29 only comes once every four years.

As we know, the earth is constantly spinning, and one 24-hour day equals one complete spin.

At the same time, the earth is orbiting around the sun and one year equals one rotation around the sun.

However, as UC Merced professor Anna Nierenberg explains, the time it takes us to circle the sun is not exactly 365 days.

"It takes 365.242 days to go around, and it's almost a quarter day extra," she said. "So if you add an extra day every four years, you can correct for that little bit of extra time, it brings you back in sync with that seasonal going around the sun."

This year we get 366 days.

That also means anyone born on February 29 called "leap year babies" actually gets their birthday this Thursday.

According to history.com, there are only about 5 million people in the world who have a leap-year birthday.