[LEAPSECS] Time math libraries, UTC to TAI

[Tony Finch]

Brooks Harris <brooks at edlmax.com> wrote:
>
> The time_t 1970 epoch is fixed with respect to internal POSIX calculations,
> but it "slips" a second with respect to UTC with each (positive) Leap Second
> introduction because "23:59:60" goes missing.

"Slip" makes it sound like a retrospective change in the relationship
between UTC and time_t, with the scales sliding against each other, but it
doesn't change - there's a fixed relationship between UTC second labels
and time_t second labels, which remains the same however many leap seconds
there are. In fact time_t is defined in terms of that relationship, and
"seconds since the epoch" is just a simplified gloss.

Tony.
-- 
f.anthony.n.finch  <dot at dotat.at>  http://dotat.at/  -  I xn--zr8h punycode
Lundy, Fastnet: Variable 4, becoming south or southeast 5 or 6. Rough or very
rough, becoming moderate or rough. Fair. Good.