Leap year trivia you might want to know
Thanks to Julius Caesar, the month of love lasts a day longer every four years. In 45 BC, the Roman emperor designated February 29 as leap day, to align the calendar with the Earth’s revolutions around the sun.
But even before the Roman calendar was set, the ancient Egyptians observed that the 365-day calendar shifted one day every four years, with respect to the seasons.
Through his Canopus decree in 238 BCE, King Ptolemaios III Euergetes had one more day added every four years, but this wasn't practiced until Augustus reformed the Egyptian calendar in 30 BCE, history buff Holger Oertel explains in his website on calendars.
As explained on Eric Weisstein's World of Science website, leap years synchronize the calendar with the seasons, because a tropical year is actually a bit more than 365 days—365.242190 days long, to be exact.
"Therefore, the year 2000 will be a leap year, but the years 1700, 1800, and 1900 were not. The complete list of leap years in the first half of the 21st century is therefore 2000, 2004, 2008, 2012, 2016, 2020, 2024, 2028, 2032, 2036, 2040, 2044, and 2048," explains the Science World article.
Even with all these adjustments, trivia geek Jay Garmon warns that the leap year system is likely to eventually "fail." "A recurring margin of error is building in the leap year system that suggests it will fail — as in, the vernal equinox will be more than a day removed from March 21 — at a particular date in the future," he writes.