Colin Perkins
The Number of the Day: 23:59:60
by Colin Perkins - September 2, 2010 - 5:20 AM

A “leap second” is a single second of time which is sometimes added into the Coordinated Universal Time in order to make it more accurately sync up with astronomical time. Leap seconds are added on an as-needed basis, and are typically tacked on as the 61st second of the last minute of June or December. The time of these additional seconds are notated as 23:59:60.

Related Fact: The most recent leap second was added on December 31, 2008. So, if that felt like a long year, now you know why.

[Source: Time and Date. See previous Numbers of the Day here.]

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Comments (8)

  1. The old saying is true. You really do learn something new everyday.

    posted by Red Bunny on 9-2-2010 at 8:13 am

  2. In December of 2008, I was successful in taking a screenshot of time.gov during the leap second.

    posted by Wolfe on 9-2-2010 at 8:26 am

  3. The fact that it was also a leap year means that 2008 was the longest year in over a decade (the last year w/ both a leap day and second was 1992).

    However, the longest year in recent history was 1972, which was a leap year, and had two leap seconds (the other was June 30th)

    posted by tkrausse on 9-2-2010 at 8:45 am

  4. I look at it as an extra second for partying! ;)

    posted by Aaron on 9-2-2010 at 10:42 am

  5. Does that mean we all celebrated 2009 a second early?

    posted by graham on 9-2-2010 at 10:50 am

  6. @ graham–only if you used Dick Clark’s on-air countdown as your timepiece :p

    I always end up asking someone what they plan to do with their second, and nobody ever gets it.

    posted by Wayne on 9-2-2010 at 11:36 am

  7. The number of the day should be 90210 as in 9/02/10

    posted by PartiallyDeflected on 9-2-2010 at 1:21 pm

  8. This means I welcomed 2009 too soon and therefore never gave it the proper welcome it deserved.

    2009 now feels dirty and overlooked.

    posted by Tyler on 9-2-2010 at 7:06 pm

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