All DateTime values shall be encoded as UTC times or with the time zone explicitly specified.
It is recommended that all xs:dateTime values be represented in UTC format.
The earliest and latest date/time values that can be represented on a DevelopmentPlatform have special meaning and shall not be literally encoded in XML.
The earliest date/time value on a DevelopmentPlatform shall be encoded in XML as '0001-01-01T00:00:00Z'.
The latest date/time value on a DevelopmentPlatform shall be encoded in XML as '9999-12-31T23:59:59Z'
If a decoder encounters a xs:dateTime value that cannot be represented on the DevelopmentPlatform it should convert the value to either the earliest or latest date/time that can be represented on the DevelopmentPlatform. The XML decoder should not generate an error if it encounters an out of range date value.
The earliest date/time value on a DevelopmentPlatform is equivalent to a null date/time value.