The main problem with the current implementation of Date and Time is that the timezone is not always explicit.
Internally, the value is maintained (=converted to/from) a neutral timezone (GMT in our case) so that consistency is maintained when passing the value between tiers.
All plug-ins (such as Construct/Split Date and Time, Serialize/Parse XML,Create/Parse JSON, Date and Time display) assume implicitly that the value should be handled in the tier's timezone (converting to/from the neutral timezone).
Trace has one problem, where on the client-side the value is shown in the neutral timezone, rather than client's timezone (see bug #205).
We plan is to provide the modeler with the functionality to allow him to specify and be informed of the timezone, as outlined in feature #204.
I think this is consistent with your findings. Please let me know if you find otherwise.
Sorry for the delayed answer, but I think you'll agree this is a rather thorny subject.
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