From The Weather Network:
Today will be the longest in three years as
timekeepers add an extra second — known as a leap second — to the
official time before Wednesday starts. Here's why.
At just after 23:59:59 p.m. Greenwich Mean Time on Tuesday, June 30, the world will experience a temporal oddity. Clocks around the world will not immediately switch over to next hour, but will pause — for just one second — before doing so.
This inserts a "leap second" into the day, giving us just a moment where the unusual sight of 23:59:60 appears on official clock faces before they switch over to 00:00:01 on Wednesday, July 1.
However,
this leap second will also produce a moment when computer systems
around the world may suffer problems, as they have in the past.
REMEMBER:
The Leap Second occurs at 23:59:60 GMT, which is 9:29:60 p.m. NDT,
8:59:60 p.m. ADT, 7:59:60 p.m. EDT, 6:59:60 p.m. CDT, 5:59:60 p.m. CST,
5:59:60 p.m. MDT, 4:59:60 p.m. PDT.
In 2012, when the last
leap second was applied, several websites experienced problems due to
the extra time, including FourSquare, Gawker, LinkedIn, Mozilla, Reddit
and Yelp. In addition, over 400 Qantas Airlines flights were delayed
when the Amadeus airline booking service went down for two hours,
forcing staff at airports to switch to manual check-ins for passengers....MORE
HT:
MetaFilter