date literals

Lars T Hansen lth at opera.com
Thu Jun 8 06:57:30 PDT 2006


Robert Sayre writes:
 > I think the date literal should allow a trailing 'Z' to substitute for
 > '+00:00'. This form is used quite a bit by authors producing similar
 > profiles, such as W3C-DTF, RFC3339, and XML Schema. Web authors will
 > have to accept the form, so the parse method should support it.

Agree.  Amended spec.

 > It looks like the grammar allows an offset of '-00:00'. That may not
 > be desirable. Here's some background on the edge cases of this family
 > of date format:
 > 
 > <http://www.imc.org/atom-syntax/mail-archive/msg13103.html>
 > 
 > "RFC 3339 gives a different semantic to a timezone offset of -00:00
 > from +00:00 and Z which xsd:dateTime (and to the best of my knowledge
 > ISO 8601) doesn't. Sect 4.3 of RFC 3339 reads:"
 > 
 >      If the time in UTC is known, but the offset to local time is
 >      unknown, this can be represented with an offset of "-00:00". This
 >      differs semantically from an offset of "Z" or "+00:00", which
 >      imply that UTC is the preferred reference point for the specified
 >      time.

Will this matter for ECMAScript?  Once a date literal is parsed it
becomes a UTC time stamp, all information about the timezone it came
from is lost.

--lars




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