2.2.2 [W3C-XSD] Section 3.2.11, gYear


The specification states:

 Since the lexical representation allows an optional time zone indicator, gYear 
 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 gYear values are considered as periods of time, the order relation on 
 gYear 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 gYear values with or without time zone indicators are totally 


Indeterminate comparisons, such 2009Z with 2010, are considered to be determinate.