Returns true if the first argument represents an earlier instant in time
than the second argument.
xs:dateTime values. Also
used in the definition of the "ge" operator.op:dateTime-less-than( $arg1 as xs:dateTime,$arg2 as xs:dateTimexs:booleanIf either $arg1 or $arg2 has no timezone component, the
effective value of the argument is obtained by substituting the implicit timezone from
the dynamic evaluation context.
The function then returns true if and only if the effective value of
$arg1 is less than the effective value of $arg2 according
to the algorithm defined in section 3.2.7.4 of
Order relation on dateTime for xs:dateTime values with
timezones. Otherwise the function returns false.