Extend DateTime classes to support time zones

[Mike Toews]

Database software usually support timestamps with time zones. In particular, PostgreSQL maps the DDL keyword "timestamp" to "timestamp with time zone" (or "timestampz") when creating tables. All other enterprise databases also support timestamps with time zones, including several client software like R, Python, etc.

This data type is not supported by FDO. Attempting to use it, such as with the OSGeo PostGIS provider, throw an error "The 'timestamptz' data type is not supported by PostGIS provider". (See also #394).

It would seem reasonable to extend the DateTime class, methods, etc. to support handling of time zones. Timestamps without time zones could simply set the time zone to Null/None, as is done with DateTime classes in other software (like R, Python, etc.)

[gregboone]

Enhancement Request