UWS times

[Paul Harrison]

> On 2016-03 -24, at 10:07, Mark Taylor <M.B.Taylor at bristol.ac.uk> wrote:
> 
> On Thu, 24 Mar 2016, Paul Harrison wrote:
> 
>> TOPCAT is a good example of a tool that is designed to work with data
>> from both VO and non-VO sources and cannot make the assumption that
>> every datetime it sees is UTC - to be able to do meaningful comparisons
>> it needs the timezone information.
> 
> Umm, as far as I remember[*], I'm afraid it makes exactly that assumption.
> In conversions it tolerates a trailing Z, but that's about it.
> Although it (sloppily) mentions ISO-8601 in various parts of the
> documentation, it will choke on many ISO-8601-compliant time strings,
> including ones with trailing [+-]hh:mm modifiers.
> 
> I never looked hard at how much effort it would be to treat all
> ISO-8601 strings properly (quite likely you can just throw them at
> some java class),

>From Java 7 it is built-in http://docs.oracle.com/javase/7/docs/api/java/text/SimpleDateFormat.html - JodaTime can be used before that.

> but I followed the restricted profile allowed
> by FITS on the grounds that it's less confusing and satisfies most
> people's requirements.  I don't recall anybody ever complaining
> about topcat/stilts's failure to work with more general ISO-8601
> strings.  So, I'd line up on the "make'em eat UTC and like it"
> side of the argument (though preferably without disrupting
> existing standards text too much if possible).

All I am arguing for is that the Z at the end should be mandatory so that it is explicit that UTC is being used.

Cheers,
	Paul.