Major Description
Because DFDLGeneralFormat.dfdl.xsd defines calendarTimeZone="UTC" dates like "7/4/1999" come through in the infoset as 1999-07-04+00:00, that is, with the trailing time-zone specifier.
The right definition for calendarTimeZone for a general purpose format is "", which means "time zone unknown".
This avoids the need for all users of DFDLGeneralFormat who have dates to override calendarTimeZone themselves to "" value, and puts the burden on them to define it if they know and want a default time zone.
Note: changing this will likely change the behavior of dateTime type as well as the date type, and we should not be taking time zone information or defaults from the local machine settings.