Missing date/time arithmetic operators/functions

Hi Jeni:
I bet you thought we had forgotten about your message
http://lists.w3.org/Archives/Member/w3c-query-operators/2003Aug/0059.htm
l !  The joint XSL and XML Query WGs approved the addition 
of the functions you recommended to the F&O document.

I did, however, make one change from the signatures you recommended.
Since the value space for yearMonthDuration is xs:integer (number of
months) and dayTimeDuration is xs:decimal  (number of seconds) I changed
the result type to xs:decimal 
and made the semantics exactly the same as op:numeric-divide with
xs:integer and xs:decimal; operands respectively.

I trust this is satisfactory.

All the best, Ashok