UWS times

[Brian Major]

On Wed, Mar 23, 2016 at 3:21 AM, Paul Harrison <
paul.harrison at manchester.ac.uk> wrote:

>
> > On 2016-03 -23, at 08:52, Markus Demleitner <
> msdemlei at ari.uni-heidelberg.de> wrote:
>

> > So, excuse me for bringing this up so late, but I think this is
> > serious enough to even make me propose an erratum if we can't fix the
> > text any more.
> >
> > This being machine readable data, I'd argue strongly we should
> > require, in effect, UTC (more exactly, timestamps without timezone,
> > since I'm not really concerned if someone uses TAI or TDB if they
> > like; there just shouldn't be time zones).
>

I have to agree that allowing time zones in the UWS 1.0 document was a
mistake.  My opinion is that the 1.1 specification should correct this by
stating that timestamps are always UTC and that an errata should indeed be
added to the 1.0 spec.


> >
> > True, that is a change that might theoretically invalidate existing
> > services, but really: Does anyone put in anything else but UTC into
> > the time fields?
>
>
> I am happy with UTC - I live in the UK and work at an observatory  - it is
> very natural for me as our computer clocks always tell UTC, but it might
> not be for others.
>
> What have people actually been doing in their implementations? I suspect
> that as most of the implementations have been connected to TAP services
> (which are probably DALI compliant) so that people have probably been using
> timestamps without timezone designators, and hopefully UTC. I imagine that
> it would not be a big disruption to change any existing non DALI timestamp
> compliant services. In java for instance it would be just a case of
> explicitly setting the timezone to UTC and then having a custom date
> formatter that did not emit the timezone specifier.
>

The CADC uses UTC in all UWS timestamps.

Introducing an errata to 1.0 could be a headache for some implementations.
Reiterating what Paul asks above: does anyone use something other than UTC?


>
> As for how much of a change to the formal standard this would be, it seems
> that as we have not reached the REC stage then this update to be DALI
> compliant can still be made.
>

Yes, I agree.

Brian
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.ivoa.net/pipermail/grid/attachments/20160323/b1db1990/attachment.html>