If Earth let all its additional quarter days add up, we’d shortly be celebrating the 4th of July when it’s snowing.
Earth, as seen from space. Credit score: NASA.
Completely happy bissextile year! Feb. 29, 2024, is leap day and marks an ongoing, longstanding correction to the calendar we use.
In most years, our calendar incorporates one year. However Earth really takes 365.2422 days (let’s name it 365¼ days) to orbit the Solar. As you may think, if we let these quarter days add up, we’d shortly be celebrating the 4th of July in America when it’s snowing.
So, we add a full day each 4 years … nearly. A 12 months that’s 365¼ days lengthy really is 11 minutes longer than Earth’s actual orbit. Which means we’d like further corrections sometimes. To refine our calendar even additional, all years evenly divisible by 400 will not be leap years.
By the way in which, the primary one added to the month of February occurred within the 12 months 8 A.D. The newest bissextile year (earlier than this one) was in 2020.
There’s additionally leap seconds. These will not be as predictable as leap years and exist as a result of the Earth spins slightly faster now than 50 years ago.
As Kate Golembiewski writes, “The Worldwide Earth Rotation and Reference Methods Service retains tabs on how shortly the planet spins by sending laser beams to satellites to measure their motion, together with different methods. When the time plotted by Earth’s motion approaches one second out of sync with the time measured by atomic clocks, scientists around the globe coordinate to cease atomic clocks for precisely one second, at 11:59:59 pm on June 30 or Dec. 31, to permit astronomical clocks to catch up. Voila — a leap second.”
This text was first revealed in 2016 and has been up to date.
