Wednesday, July 20, 2016

It's not too early to start planning what to do with the "leap second" we'll be getting New Year's Eve


Tim Hornyak took this photo in Tokyo on June 30 of last year, as this clock presumably ticked down to the addition of the last leap second.

by Ken

You know how we're always complaining that our lives are so tightly scheduled that we don't have a second to spare? It's in thi spirit that, ever since I heard the news that a "leap second" is being added to the official time-keeping apparatus on New Year's Eve -- so that instead of clocks going from 11:59:00 to 12:00:00 they're going to go from 11:59:59 to 11:59:60 and then on to 12:00:00 -- I've been barely able to contain my excitement. Think of it, a whole extra second, to do with whatever we will, at no charge, with no excuses or apologies called for, and nobody to answer to. The only hitch I can see is that you have to take it; otherwise you'll spend 2016 a second behind the rest of the world.

I can't explain very well where the extra second is coming from. I know, though, that it has something to do with the earth's rotation being unpredictable, though this unpredictability is apparently predictably on the slow side, so that every now and then, either at the end of June or at the end of December, the astronomers or physicists or whoever's in charge have been adding a leap second here or there, never subtracting one.

The official proclamation of the next leap second (click to enlarge).

The last time this happened, on June 30 of last year, a fellow named Peter Whibberley, described as "senior research scientist at the UK's National Physical Laboratory (NPL)," where he works in the time and frequency group, explained (for want of a better word) to the BBC, "Because they depend on measurements of the Earth's rotation, which varies unpredictably, leap seconds occur at irregular intervals."

Now this kind of alarms me, this business of the earth somehow dragging randomly. None of the responsible scientists seem to be pointing accusing fingers but a person can't help wondering whether the planet is just kind of dogging it from time to time, and leaving us to lump it. Or it could be some simple matter, like some of the earth's component parts having swollen a little somewhere, or there's maybe an umbrella or something ever so slightly stuck in the works, or somewhere somebody's pulling when they should be pushing.

It bothers me a little that these scientists don't seem to be focused on the root cause. I know there was some kind of big meeting of the United Nations' World Radio Committee in November, but WRC-15 seems mostly to have punted till WRC-23. Maybe the thinking is that by 2023 either nobody will care or it'll be somebody else's problem.


One group that's mad as hell is the world IT community. (See PCWorld's report, "Latest leap second plan poses a dilemma for conscientious sysadmins.") The thing is, there's no way that the extra seconds can be preprogrammed into their systems; they have to be added manually. As our UK mate Peter Whibberley explained to the BBC last year (and remember, this goes back to last June and before, so there's no blaming this mess on Brexit):
Leap seconds are announced only six months in advance. This means computers and software cannot be supplied with leap seconds programmed in, and they must be inserted manually.
You probably won't be surprised to learn that our Mr. Whibberley (say, do you suppose that's really his name?) had still more to say:
Getting leap seconds wrong can cause loss of synchronisation in communication networks, financial systems and many other applications which rely on precise timing.

Whenever a leap second occurs, some computer systems encounter problems due to glitches in the code written to handle them. The consequences are particularly severe in the Asia-Pacific region, where leap seconds occur during normal working hours.
AS IDG News Services's Peter Sayer put it in the PCWorld piece:
The dilemma for sysadmins next New Year's Eve, then, is whether to stay on duty when everyone else is partying in order to minimize the effects of the coming leap second. Or whether to turn off their pagers, tell themselves that whatever will be, will be -- and let the ensuing chaos stand as testimony to WRC-23 delegates that the leap second's time is up.


My original plan was to put together a neat list of things a person could do with that extra second coming up on New Year's Eve. Then it occurred to me that any time I put into this project beyond the one-second mark would represent a net time loss. So you're on your own for ideas. I aay, go crazy!

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