So in DFDLGeneralFormat.dfdl.xsd, which is built-in to Daffodil, there is a binding for dfdl:calendarTimeZone="UTC".
That seems ok, but if you import a date like "07/04/1999" you get an XML date like:
That is, you get a UTC time zone specifier on any date.
This is really undesirable in that it is unexpected. Perhaps the value for dfdl:calendarTimeZone should be "" (empty string), meaning no time zone assumed. Changing that results in the right behavior in the XML infoset
of 1999-07-04, which is what people expect.
Only issue is changing this is, technically, incompatible backward.
But the alternative is every schema where dates are used, where the timezone isn't supposed to be specified, is going to have to override the default of "UTC" with "" by itself.