[time-nuts] Leap Quirks

[Chuck Harris]

Poul-Henning Kamp wrote:
> In message <495FB615.9080200 at rubidium.dyndns.org>, Magnus Danielson writes:
> 
>>> Having a message from ntp.c that says there was a leap
>>> to HH:MM:60 implies that HH:MM:60 is a valid time as far
>>> as ntp.c's author is concerned.
>> It is valid UTC time, not valid POSIX time, which are two different things.
> 
> Well, it is a valid POSIX time, but it means a second later than
> desired in this case, because the 60 is taken as 60 seconds, and
> folded into a minute-roll-over.
> 
>>> Having used unix since edition V, I am also aware of how unix
>>> systems count off seconds since the epoch 1/1/1970.  But that
>>> really is immaterial to the discussion.
> 
> No, that is actually the crux of the matter...

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?

It is my understanding that it cannot.  I believe that time_t must
increment by one as each second passes, and must contain the number of
seconds that have passed since the unix epoch on 1/1/1970... without
regard for leap seconds.

I was of the understanding that the problem was in how the UTC time was
calculated from time_t, and the converse.

Do tell!

-Chuck Harris