Conflicting standards

Got to love it when one standard says to either use a date format like CCYY-MM-DD or CCYY-MM-DDTHH:MM:SSZ and the other says only CCYY-MM-DD is allowed. In this case the outside XML container uses the verbose granularity whilst the encapsulated part only uses the small ISO 8601 variant, of which MM and DD are optional too.