2.2.4 [W3C-XSD] Section 3.2.13, gDay


The specification states:

 Since the lexical representation allows an optional time zone indicator, gDay 
 values are partially ordered because it may not be possible to unequivocally 
 determine the order of two values one of which has a time zone and the other does 
 not. If gDay values are considered as periods of time, in an arbitrary month that 
 has 31 days, the order relation on gDay values is the order relation on their 
 starting instants. This is discussed in Order relation on dateTime (§ 
 See also Adding durations to dateTimes (§E). Pairs of gDay values with or without 
 time zone indicators are totally ordered.


Indeterminate comparisons are considered to be determinate.