[LEAPSECS] Crunching Bulletin B numbers (POSIX time)

[Tony Finch]

On Tue, 22 Feb 2011, Keith Winstein wrote:

>


You made several good points though I have some minor niggles.


> Calculations further in the future, though, still won't be "functional" and

> will change their results when new leap seconds are loaded into the zoneinfo

> files. This seems to be to be an artifact of having intercalary seconds in the

> local time scale at all -- whether they are in time_t (as in POSIX) or in the

> conversion to localtime (as here), it seems to be the same problem either way.


It isn't that bad if the intercalation is predictable. Even better if it
can be hard-coded, as in arithmetic calendars.

Note that POSIX time has no intercalation: it is a version of traditional
universal time. Specifying it in terms of UTC is mostly a red herring,
especially since POSIX doesn't specify how time_t is synchronized.

Tony.
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