In message: <[email protected]> "Poul-Henning Kamp" <[email protected]> writes: : In message <[email protected]>, 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.
It is a valid POSIX struct tm time. But it doesn't represent a leap second. Instead, like you say, it wraps to the next minute. There are not POSIXly compliant time_t values that will map to the leap second value (23:59:60). It is not possible to represent the leap second in a time_t. : >> 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... Yes. Such a simple definition gives so many possible ways to interpret it. The POSIX "there are no leap seconds" way. The prior + accumulated leap seconds. And also the prior, plus the extra time that accumulated between 1970 and 1972 in the UTC time scale... But that last one is kinda hard since it isn't an whole number of seconds. I've seen timescales try to use all of these definitions at one point in my career or another (plus a boatload of others that seemed like a good idea at the time to the inventors). Warner _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
