I actually had never heard of today’s feature–nor had my mom.  Evidently, the earth’s orbit is somewhat irregular.  Atomic clocks, first appearing in the 1950’s, were extremely accurate, but these deviations in the earth’s orbit would eventually mean our time would be off by a second, then a minute, and eventually hours over the course of thousands of years.  And since we are such a scientifically precise society, this is unacceptable.  Therefore, on this date in 1972, the first leap second was added to the clocks.

There is no set time for the leap seconds to be added.  Scientists watch the differences in atomic and solar time, and when the time is expected to be .6 seconds discrepancy, scientists announce the addition of a leap second six months in advance.  It doesn’t make any difference to most of us, but those who rely on precision in their jobs really do tend to struggle.  In fact, rocket launches are never scheduled on these days.   It seems like this may cause computer problems for some as well.  From what I can tell, there have been a total of 25 leap seconds added since this time, the last one occurring on June 30, 2012.  Some countries want leap second abolished, and it seems like this is still an issue that has yet (if ever) to be resolved.

For more information:

http://www.abs-cbnnews.com/lifestyle/06/28/12/leap-second-june-30-1-min-last-61-secs

http://www.foxnews.com/scitech/2012/01/06/time-keepers-to-introduce-leap-second-june-30/

http://en.wikipedia.org/wiki/Leap_second

http://famousdaily.com/history/1-leap-second-added-to-utc-time-system.html