RE: xslt 2. Date arithmetic.

Thanks Pieter, David, for the answers:
 

    -----Original Message-----
    From: Michael Kay
    
    The difference between two dates is a dayTimeDuration (if 
    they're in the same timezone - the usual case - then it 
    will be an integer number of days).

Great. No problem with that. Since the output is for humans
can I cast that to something sensible? I was trying to get
yearMonthDuration.
    
    Subtraction of dates to give a yearMonthDuration - the old 
    subtractDateTimesYieldingYearMonthDuration - has been 
    removed (as befits any function with such a ridiculous 
    name) because it proved too difficult to specify it.

OK, but the functionality of that seems reasonable?


 For 
    example, would you expect 2005-02-28 minus 2005-01-31 to be 
    one month, on the basis that 2005-01-31 plus one month is 
    2005-02-28? But surely the difference between these two 
    dates is the same as 2004-02-28 minus 2004-01-31?

Subtle, but I can see the problem. How long is a month?

    
    Depending what you actually want to achieve, the best 
    approach is probably to extract the year/month components 
    (year-from-date(), month-from-date()) and manipulate the 
    values yourself.

which matches DC's suggestion? 

OK, I'll play with that.
Thanks Michael.

regards DaveP

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