Leap Second

December 31st will be a long day this year. One second longer, to be exact. The earth's trip around the sun doesn't exactly correspond to our calendar, as it takes 365.2422 days. That's why we add a day for leap year every four years, but it still doesn't come out even, so every once in a while, another second is added to the last day of the year.
The International Earth Rotation and Reference Systems Service is the organization that monitors the difference in the two timescales and calls for leap seconds to be inserted or removed when necessary. Since 1972, leap seconds have been added at intervals varying from six months to seven years — the most recent was inserted on Dec. 31, 2005.

Link -via Metafilter

(image credit: Flickr user slack12)

Newest 5
Newest 5 Comments

The leap second has nothing to do with the length of the year. They are added because the earth's rotation has slowed (and continues to slow), which puts the "sun overhead at noon" terrestrial time out of synch with the atomic clocks.

And contrary to TwoDragons' conjecture, you get to play with a lot of expensive toys.
Abusive comment hidden. (Show it anyway.)
*falls over laughing at Ali S.* "NARF!"

Calculating and inserting leap seconds must be a very, very...very...very dry job. I can't help but imagine a bunch of crusty old bean-counters playing with clocks.

Abusive comment hidden. (Show it anyway.)
Login to comment.

Email This Post to a Friend
"Leap Second"

Separate multiple emails with a comma. Limit 5.


Success! Your email has been sent!

close window

This website uses cookies.

This website uses cookies to improve user experience. By using this website you consent to all cookies in accordance with our Privacy Policy.

I agree
Learn More