Earth adds leap second Saturday night
 

Saturday night will stretch longer by a second. A leap second.
International timekeepers are adding a second to the clock at midnight universal time Saturday, June 30, going into July 1. That's 8 p.m. EDT Saturday. Universal time will be 11:59:59 and then the unusual reading of 11:59:60 before it hits midnight.

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A combination of factors, including Earth slowing down a bit from the tidal pull of the moon, and an atomic clock that's a hair too fast, means that periodically timekeepers have to synchronize the official atomic clocks, said Daniel Gambis, head of the Earth Orientation Service in Paris that coordinates leap seconds.
The time it takes the Earth to rotate on its axis -- the definition of a day -- is now about two milliseconds longer than it was 100 years ago, said Geoff Chester, spokesman at the U.S. Naval Observatory, keeper of the official U.S. atomic clocks. That's each day, so it adds up to nearly three-quarters of a second a year.
Timekeepers add that leap second every now and then to keep the sun at its highest at noon, at least during standard time. This is the first leap second since January 2009 and the 25th overall. Gambis said the next one probably won't be needed until 2015 or 2016.
There should be no noticeable affect or inconvenience on computers or any other technology that requires precise timekeeping because they adjust for these leap seconds, Gambis said Friday.
Earlier this year, official timekeepers from across the world discussed whether to eliminate the practice of adding leap seconds. They decided they needed more time to think about the issue and will next debate the issue in 2015.
So for now, Chester said, "you get an extra second, don't waste it."


Read more: Earth adds leap second Saturday night | Fox News

Did I miss it last night. I was away. That was a very good read

Despite precautions by system providers, an extra second added to the official timekeeping record Saturday triggered several popular Internet services to crash over the weekend, including LinkedIn, Reddit and Quantas airline's reservation system.

Among systems that reportedly experienced difficulty with the extra second were unpatched Linux OS kernels, Hadoop instances, Cassandra databases and Java-based programs. Enough problems were documented around the globe that some even likened leap second change to another Y2K.

Leap seconds were introduced in 1971, as way to synchronize official digital time keeping, called Coordinated Universal Time (UTC) and mean solar time, namely by adding or removing a second from the official time. Overseen by the International Telecommunications Union, UTC is defined by the accumulation of seconds, which are defined with great precision by atomic clocks. Solar time, in contrast, measures the day by the time it takes the Earth to do one complete rotation, which can fluctuate slightly due to tidal effects, the slowing of the earth's rotation and other factors.

On Saturday, the ITU added a second onto the end of June 30 UTC, at midnight Greenwich Mean Time, or 8 PM eastern daylight time, the 25th adjustment to UTC since 1971.

Typically, UTC is coordinated across the Internet using the Network Time Protocol (NTP), in which the official time, supplied by the U.S. Navy and other sources, is passed among Internet servers. The client software for NTP can be configured to accommodate the leap seconds when they occur. Additional solutions have been offered to better arm servers against possible leap second failures, including those introduced by Opera and Google engineers.

For this leap second however, numerous problems were experienced. Those with servers running Debian Linux had reported several servers going offline after the leap second occurred. The servers were restored after NTP was temporarily disabled.

Reddit reported failures, stemming from its use of the Cassandra database and programs written in Java (although Reddit may have also been affected by storm related power outages that also took place Saturday in the Northern Virginia area). Mozilla also reported on leap second issues, stemming from Java. Mozilla's deployments of Hadoop, which heavily use Java, needed to be restarted. DataStax, which manages development of the open source Cassandra database, did not immediately respond to a request for comment.

The reservation system for Australian airline Quantas also reportedly went offline due to a leap second crash. LinkedIn also experienced uptime difficulties following the leap second.

The issue with Linux stemmed from a deadlock, a patch for which was released in March.

The ITU has considered eliminating leap seconds because of the problems they can cause IT systems.

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What you missed in that leap second ...

I feel so much older now ...