The Leap Second of 2015

By Joseph Roten


What the heck is a Leap Second and when?

On Tuesday, June 30, 2015 at 23:59:59 UTC, the IERS - International Earth Rotation and Reference Systems Service (Yes, there really is such a group), will be adding a second to the worlds master atomic clocks. This is needed to bring the clocks back into agreement with astronomical time. Basically, every few years, a second is added or removed so as to keep our clocks, in agreement with the Earth's rotation.

Note: UTC is Coordinated Universal Time. This is the time zone in which the Royal Observatory in Greenwich England is located. For many centuries, it was the clocks at the Royal Observatory that served as the worlds master clocks. Even thought this is no longer the cast, we still use UTC as the default time zone when talking about world time.

Whenever a leap second is added or subtracted from the atomic clocks, the time change is automatically be passed down to the Internet time servers, then to other servers who get their time from those, and on down until it reaches all the workstations, laptops, routers, and cell phones of the world.  This is done by the NTP (Network Time Protocol), which is simply a way for one computer to ask “Hay, time server, what time is it?” out to the Internet. A time server will then reply with the EXACT time, down to a fraction of a second.

The last time a leap second was added was on Saturday, June 30, 2012. This caused a few minor problems, but nothing very serious.
The most noted one was that the booking computers for Qantas Airways choked on the time change and were down for a few hours. Flight attendants were forced to check some passengers in by hand. Which of course wasn’t really a big issue; more like a big hassle for the attendants and passengers,
Some types of GPS receivers with older software started recording the wrong date to their logs. This issue has been resolved with software upgrades. 
And a few popular web sites like Reddit and Mozilla experienced “brief technical problems” which were resolved within a few hours. 


So...What does this have to do with Linux Mint?
      Actually....nothing at all.
            Which is kind of the point you see.
                  Linux Mint is NOT affected by such a change.


Linux Mint (and Linux in general) will handle this event without any issues.
The code that was the source of the “glitches” in 2012 has long since been corrected.
Many in the Linux community, including Linux's creator Linus Torvalds, see this event very much as a tempest in a teacup. Everyone who is familiar with this event are saying that there shouldn't be any issues at all this time.

See “Linux’s Creator Wants Us All to Chill Out About the Leap Second”
at http://www.wired.com/2015/01/torvalds_leapsecond/



History in the making: This might be the last Leap Second event.

There is a chance that this 2015 Leap Second event might be the last one. There has been a debit over the past 15 years to have the Leap Second ideal abolished entirely, and just allow the worlds clocks be a second or two out of sync with the Earth's rotation. In the past few years, momentum has been growing towards this. It will most likely be brought up once again this coming November during a conference in Geneva, and this time, the Leap Second ideal might be done away with.

Other than a few specialist like astronomers, GPS technicians, and people involved with the deep space network, there is little piratical need for the world atomic clocks to be 100% in sync with the Earth's astronomical time. A few seconds out of sync with the Earth rotation would not matter to the average person. All that really matters is that all the atomic clocks and Internet Time servers are in agreement about what the current time is.  

If you are interested in reading more about the possible abolishment of the Leap Second, I would suggest the blog entry:
“The Leap Second Is About to Rattle the Internet. But There’s a Plot to Kill It”,
By Robert McMillan
at http://www.wired.com/2015/01/leap-second-rattle-internet-theres-plot-kill/



What time will this Leap Second happen?

This leap second will happen on Tuesday, June 30, 2015 at 23:59:59 UTC.

For the US time zones, this works out to be....

    Easter Standard Time........Tuesday, June 30, 2015 at 7:59:59 PM
           New York City, USA East Coast

    Central Standard Time.........Tuesday, June 30, 2015 at 6:59:59 PM
          Chicago, Dallas     

    Mountain Standard Time.........Tuesday, June 30, 2015 at 5:59:59 PM
           Denver

     Pacific Standard Time........Tuesday, June 30, 2015 at 4:59:59 PM
           Seattle, USA West Coast

To convert the time of this event to another time zone, there is a handy calculator to do so at:
http://www.timeanddate.com/worldclock/converter.html


That's all for this time. Thanks, Joe.