'Leap Seconds' May Be Eliminated From UTC

angry tapir writes "Sparking a fresh round of debate over an ongoing issue in time-keeping circles, the International Telecommunications Union is considering eliminating leap seconds from the time scale used by most computer systems, Coordinated Universal Time (UTC). Since their introduction in 1971, leap seconds have proved problematic for at least a few software programs. The leap second added on to the end of 2008, for instance, caused Oracle cluster software to reboot unexpectedly in some cases."

Comments

Poor solution

[LostMyBeaver]

The proper solution is to make programmers aware of leap seconds. There are 86400 seconds in a normal day, however there is an additional second added once or twice a year to adjust for solar time.

Wikipedia documents it quite well and programmers in modern times should be heading to wikipedia almost constantly anyway. The real problem occurs when the date/time is given in seconds since an "event" such as Jan 1, 1970. Most programmers don't know about leap seconds and I must admit, I don't generally bother calculating for them. But if it were necessary, it would be relatively trivial to do so.

We shouldn't remove fixes to the clock just because programmers are undereducated. I'm quite convinced that just posting this on Slashdot will raise awareness across a high percentage of the programming world.

I also always wondered why undergraduate studies for computer science didn't make time a relevant issue. It seems as if it's one of the more complex topics and yet, we don't pay any attention to it. Last formal education I had on time (not talking about physic related, but calendar) was in primary school. There are so many time systems out there that we should pay more attention to educating programmers on it.

Re:Poor solution

[Thorsett]

Why adjust for solar time?

We adjust for solar time because UTC is an astronomical timescale, not a "count of seconds since a specific time." If "computer people" want a timescale that ignores leap seconds, they can use an atomic timescale like TAI (or GPS time, which is a constant offset from TAI). But choosing to standardize the internet on UTC and then complaining it is too hard to do the programming right is a little like buying a house next door to a turkey farm and complaining about the smell.

Changing time because of Oracle?

[koinu]

Leap seconds are handled well, when the system supports it well and the software is not utter crap.

I am always annoyed when people break basic things to make software work (e.g. hardware, also see ACPI). Now they are not only breaking hardware, but redefining measurements to make buggy software work. What comes next?

I can understand when something is changed for convenience purposes (to have simpler calculations), but justified with buggy software is plain wrong. And I surely don't care if an Oracle database "reboots"... whatever that might mean.

Ok...

[Chyeld]

Isn't this like legislating that PI is 3.14 because some people have problems with the idea of irrational numbers? If programs have issues with leap seconds, it sounds like programs weren't written properly, not that the spec needs to be rewritten to accommodate this flaw. Would these same people have demanded that it be 1999 again to avoid all the costs of the Y2K fixes?

Let's see if I've got this right

[Joce640k]

We have to make every clock in the world inaccurate because Oracle's software is crap...?

Re:Let's see if I've got this right

[WiglyWorm]

Pretty typical "let future generations deal with it" thinking. Why don't we just have Oracle fix their code?

Re:Let's see if I've got this right

[Kjella]

Daylight Savings has had numerous studies showing reduced electricity consumption.

Yes, the question is more if there's more or less hassle to have summer and winter opening hours than to change "time" itself.

Re:Let's see if I've got this right

[AltairDusk]

Flight industry and safety equipment also goes through very stringent testing. If the capability to handle leap seconds isn't included in their battery of tests then they have a hole in their testing procedure.

Re:Let's see if I've got this right

[mangu]

They exist because the SI day is slightly shorter than the solar day, by a tiny fraction of a second.

Wrong. They exist because the solar day is getting longer every time. The tides caused by the moon are slowing down the earth's rotation rate.

safety-critical systems that depend on time synchronisation and don't reliably work with leap seconds

They should. If a programmer is so incompetent he can't get leap seconds right, I shudder to think what else he did wrong.

Re:Let's see if I've got this right

[TheRaven64]

No it can't, for three reasons. Firstly, leap days are deterministic. They happen based on a set of simple rules. If the year is divisible by 4, you get a leap year, unless the year is divisible by 100 but not by 400. Leap seconds, in contrast depend on a variable that changes daily, so are not predictable. They are fudged in with a few months notice, requiring every computer that needs to deal with them to be updated regularly.

Secondly, leap years don't violate basic sanity checking rules. You can assert that every month is 28-31 days, and that's not broken by leap years. You can assert that every minute contains 60 seconds. In the last decade, that has been true for 2,106,718 minutes, and false for 2. In every year before 1970, it was true.

Finally, leap years solve a real problem. The point of a solar calendar is that the seasons are in the same place every years. Having the seasons move made it difficult for people to plan when to plant crops. It's less important now, but having the seasons move around would be noticeable for everyone and irritating for a lot of people. In contrast, the only 'problem' that leap seconds solve is that the sun is not at its highest above the meridian at precisely 12:00. As the poster above you pointed out, the skew from not having leap seconds for a thousand years makes less of a difference to the position of the sun than simply not living quite on the meridian.

Leap seconds are a (very) complex solution looking for a problem.

Re:Stupid

[bickerdyke]

Why abolish it?

You're free to CHOOSE your timescale! GPS, UTC, UT1, TIA.....

So if leap seconds confuse you, use a timescale without them. Thats what they're for. But keep the timescale that's supposed to be in sync with earth rotation in sync with earth rotation!

That's not a solution

[Nicolas MONNET]

Clocks should strive to give the most accurate measurement, not lie to their users.

The solution exists, it's TAI. You use TAI internally and convert to UTC (or your TZ) when displaying, similar to unix time.