RE: Time in oBIX

I think we should avoid if at all possible allowing in an extension spec, things that are prohibited by the core spec.

From: obix@lists.oasis-open.org [mailto:obix@lists.oasis-open.org] On Behalf Of Considine, Toby
Sent: Wednesday, May 08, 2013 9:21 AM
To: obix@lists.oasis-open.org
Subject: [obix] Time in oBIX

This brings some interesting questions forward.

Z may be expressly forbidden in the core spec. Do we need to allow options for its use in the advanced telemetry (2.0)?

IIRC the original meetings, we discussed that buildings are *scheduled* in local time, whatever it may be. One integrator presented the specific issue of setting the opening schedule for a chain of 100 stores in 5 states (and multiple time zones). We also discussed the issue that a 9:00 opening is still a 9:00 opening on either side of a DST change.

In calendars, there is an explicit notion that you can accept a schedule in local time (no time zone or prefix), or in time zone (DST or not), or in Zulu time. However one receives the request, and however one processes the request, one must always store the type of the original time. If the request was for Eastern Standard Time (EST), then one should *not* recompute when EDT begins. Alternately, when the request was for ET, one *must* recomputed when DST begins.

We may want to revisit *some* of the time notions in oBIX.

"When one door closes, another opens; but we often look so long and so regretfully upon the closed door that we do not see the one which has opened for us."

-- Alexander Graham Bell

Toby Considine

Chair, OASIS oBIX TC

Editor, OASIS EMIX, Energy Interoperation
Campus Services Information Technology
University of North Carolina
Chapel Hill, NC

Email: Toby.Considine@ unc.edu
Phone: (919)962-9073

http://www.oasis-open.org
http://www.NewDaedalus.com

From: obix@lists.oasis-open.org [mailto:obix@lists.oasis-open.org] On Behalf Of Gemmill, Craig
Sent: Wednesday, May 08, 2013 6:58 AM
To: Chris Bogen; obix@lists.oasis-open.org
Subject: RE: [obix] Groups - oBIXfigure1UML.png uploaded

Hi Chris-

I think I can answer this somewhat. The <date> and <tz> concepts were added in the initial 1.1 drafts. I don’t think that part has really ever seen a peer review of this level. I think date & time should use a uri as their units – this is stated in the unit facet definition. I don’t think tz makes as much sense for date & time, but it is there. I noticed some inconsistencies in the spec language in those areas too (time example has the expressly forbidden trailing ‘Z’, both describe behavior when using a timezone, although that is forbidden). I have corrected the spec. Regarding c), reltime has the units embedded in the value, e.g. PT10S implies 10 seconds.

Craig

From: obix@lists.oasis-open.org [mailto:obix@lists.oasis-open.org] On Behalf Of Chris Bogen
Sent: Tuesday, May 07, 2013 4:02 PM
To: obix@lists.oasis-open.org
Subject: [obix] Groups - oBIXfigure1UML.png uploaded

Submitter's message
I uploaded a draft version of a new Figure 1 for the next working draft. I can arrange it to look better in the final version, but wanted to get feedback first.

My goal was to represent the object model in UML class diagram notation, but with a little more detail. As it currently exists Figure 1 is technically a very simple UML class diagram. Major changes:

1) I added namespace/package prefixes to distinguish between oBIX and native or xsd mapped types. As it is the diagram is ambiguous.

2) Represented "val" as a proper parameterized class with type binding relations from subclasses.

3) Added the "status" enumeration for clarification.

There are some issues that I found while making the diagram, such as...
a) why does int use a uri for units while date uses a string?

b) In facets there is discussion about using tz in abstime, date, or time, but in the current Figure 1, tz is not an attribute of those classes.

c) related to b, why doesn't reltime have units?

Regards,

Chris
-- Chris Bogen

Document Name: oBIXfigure1UML.png

Description
A draft revision of the oBIX Figure 1 illustration
Download Latest Revision
Public Download Link

Submitter: Chris Bogen
Group: OASIS Open Building Information Exchange (oBIX) TC
Folder: Contributions
Date submitted: 2013-05-07 13:01:51

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