[time-nuts] Leap Quirks
phk at phk.freebsd.dk
Sun Jan 4 04:44:33 EST 2009
In message <4960027E.1000103 at erols.com>, Chuck Harris writes:
>Poul-Henning Kamp wrote:
>>> Ok, that is news to me. Are you saying that (pulling a number out of
>>> the air) time_t = 21120123 could be followed by 21120123 on a year where
>>> we added a leap second?
>> Apart from the number, that is exactly what happens: The last
>> second of the (UTC) day is recycled twice.
>[...] and all of the sources I have found
>concur that time_t is the number of seconds since 1/1/1970 UTC without
>regard to leap seconds.
>When did this change?
Never, that's the trouble.
time_t is better defined as:
d * 86400 + min(rs, 86399)
d = Number of complete days since 1970-01-01H00:00:00Z
rs = number of seconds since UTC midnight.
Eliminating leapseconds would make it correct however.
Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
phk at FreeBSD.ORG | TCP/IP since RFC 956
FreeBSD committer | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.
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