Portable general timestamp format, not 2038-limited

Peter J. Holzer hjp-usenet2 at hjp.at
Wed Jul 4 08:27:33 CEST 2007


On 2007-07-04 00:14, Dr.Ruud <rvtol+news at isolution.nl> wrote:
> Peter J. Holzer schreef:
>> Since a day with a leap second has 86401 seconds (or 86399, but that
>> hasn't happened yet)
>
> Many systems allow a seconds value of 0..61, so minutes (actually
> months) with two leap seconds are foreseen.

That comes from the ANSI C standard. It is unclear why the standard
specifies 0..61 instead of 0..60. The most plausible explanation I've
read is that it's the result of a misunderstanding: Up to two leap
seconds in a year are expected, and somebody thought they would be
applied both at the end of the year (instead of one at the end of each
semester).


> A leap second may be introduced at the end of any month, the preferred
> dates are at the end of June and the end of December.
>
> At the estimated rate of decrease, the earth would lose about 1/2 day
> after 4,000 years, and about two leap seconds a
> month would be needed to keep UTC in step with Earth time, UT1.

C is already ready for this, although I doubt that it's authors planned
that far ahead.

	hp


-- 
   _  | Peter J. Holzer    | I know I'd be respectful of a pirate 
|_|_) | Sysadmin WSR       | with an emu on his shoulder.
| |   | hjp at hjp.at         |
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