martin.burns (4/6/2012 8:07 AM): An ESPI data file as used for Green Button, for example, currently has no time zone information. The third party will not necessarily know the time zone that the data is for (the UsagePoint). Therefore, he can't render it to the Retail Customer in the appropriate time zone.

 

Therefore it seems reasonable that the data must have only UTC and that time zone and DST information needs to be added to the UsagePoint definition.

 

I suppose alternatively, a hint at the time zone information could be deduced from the atom publishing part of the data but this seems unsatisfying as it is header information that might not be retained in a user's application.

steve.van ausdall (3/19/2012 4:48 PM): RFC 3339 is only used "for the above parameters" which are published and updated max and min (query parameters). Atom (RFC 4287) defines published and updated using xsd:dateTime, which is similar to ISO 8601 (allows specification of time zone), and ESPI uses "TimeType" which is similar to unix time (UTC / no time zone). If the field in question allows specification of a time zone, then times can be specified in relation to a specific time zone, but it is not required. The service provider (DataCustodian) does not need to know the time zone of the service consumer (AuthorizedThirdParty). The third party may need to convert times specified without time zone to local time for display purposes.