[time-nuts] Re: UTC - A Cautionary Tale
M. Warner Losh
imp at bsdimp.com
Mon Jul 18 18:03:40 EDT 2005
In message: <22.214.171.124.0.20050718174733.03eaeb20 at mjs.alientech.net>
mikes at flatsurface.com (Mike S) writes:
: At 04:36 PM 7/18/2005, M. Warner Losh wrote...
: >: By attempting to ignore an intrinsic reality, we are making such
: >: issues more likely, not less. How about an extension to ISO 8601
: >: that would permit distinguishing timescales, something like:
: >: 2005-07-18T12:34:56Z (UTC)
: >: 2005-07-18T12:35:28A (TAI - same instant)
: >: Multiple timescales will always exist. We should acknowledge that
: >: fact and move on.
: >The reason that 'Z' is used for UTC is that A-X are used for all the
: >other time zones on the planet (well, all the ones that fall on hour
: >boundaries). I'm unsure if 'Y' is free or not for TAI.
: If I'm not mistaken, IS 8601 only uses "Z," all other timezones are expressed within the notation as an offset. ex. of EST time: "2005-07-18T05:58-05:00" Using "A" would cause no conflict. I'm pretty sure "Z" (or Zulu) comes from the "Zero Meridian," not because it was an afterthought which used one of the letters which was left over.
Well, it was first assigned, but I thought that the other time zones
had a standard letter. I've seen tables that list them, but I don't
know if they are standard. Maybe an obsolete standard of which only Z
has survived :-).
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