Returns true if the first argument represents a later instant in time than
the second argument.
xs:dateTime values. Also
used in the definition of the "le" operator.op:dateTime-greater-than( $arg1 as xs:dateTime,$arg2 as xs:dateTimexs:booleanThe function call op:dateTime-greater-than($A, $B) is defined to return the
same result as op:dateTime-less-than($B, $A)