[LEAPSECS] No leapseconds on trains

Zefram zefram at fysh.org
Thu Nov 17 06:47:44 EST 2011


Paul J. Ste. Marie wrote:

>This is abundantly clear


Clear, but in the POSIX standard it's immediately redefined to mean
something other than what it clearly says. It defines "seconds since
the epoch" to be a numerical encoding of UTC timestamps, *not* a linear
count of seconds. The MVB standard seems to be best read as incorporating
that definition.


> Absolute number of SI seconds since

>1970-01-01Z00:00:00 doesn't change with or without leap-seconds.


Yes. However, 1970-01-01 is in the rubber-seconds era of UTC. So, if
taking it literally, are the "seconds" meant to be UTC seconds or TAI/SI
seconds? It doesn't say which, and there are more of the latter than of
the former. Either way, the number of seconds from 1970-01-01T00:00:00.0
UTC to (say) 2011-01-01T00:00:00.0 UTC is not an integer. I don't think
*anyone* genuinely counts seconds from 1970-01-01T00:00:00 UTC.

-zefram


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