timestamps in sasl
Richard A. O'Keefe
Tue Aug 26 01:53:59 CEST 2003
Per Bergqvist <per@REDACTED> thinks that SASL timestamps should be UTC.
Pro: no timezone information required.
Pro: no confusion when clocks reset (so some times "happen" twice)
Pro: files transportable to machines in other time zones without change
Con: potential for human error; people looking at the timestamps will be
surprised by what they see.
Con: I've been told that Windows doesn't actually _know_ what the UTC time
is; was that true and if so is it still true?
Con: UNIX doesn't actually know what the UTC time is either; UNIX firmly
believes that every day has exactly 86,400 seconds and in UTC that
just isn't true. Up to two days in a year may have an extra second,
and there is no formula saying which years get leap seconds. I used
to have a table giving historic leap seconds, but it is way out of
date and I don't remember where to get current information.
With respect to the last point, presumably UNIX "fake" UTC which ignores
leap seconds (in effect saying that up to two of the seconds in a year
may take twice as long as all the other seconds...) would do just as well.
For me, the fact that a local time T1 that is less than a local time T2
may actually indicate a _later_ time (due to the clocks being reset at
a daylight saving transition) makes local time too unreliable to take
seriously for any kind of time stamp.
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