Does a year really Leap?

Every 4th year, February gets an extra day, the 29th. This gives us a calendar year that's 365-1/4 days long. But how exactly is it a "leap year" if we make the year longer? How is that leaping over anything? It's more of a drag year, because it drags on for an extra day. This is a good example of how priorities have changed. The reason it's called a leap year is ... because it makes fixed festival days "leap" ahead one day in the week. The term goes back to Middle English.

By the way, this calendar we use is called the Gregorian calendar, named after Pope Gregory XIII, who declared its use on Feb. 24, 1582. It replaced the older Julian calendar whose year was a little bit too long, and even skipped 10 days to try and get caught up. It's an interesting story.

To be exact, our actual year is 365.242 days, and a leap year was defined as "every year divisible by 4 except for centenary years not divisible by 400", which does a good job. But since modern astronomers and other scientists need more precision, the National Institute of Standards and Technology adds "leap seconds" as needed to keep us in synch with reality.

Note that there are other calendars in use in other parts in the world right now. We take time for granted, but time-keeping is not a simple matter.