$calc($ctime(8/9/2004) - $ctime)
This calculates the the number of seconds from now ($ctime) till 8/9/2004 ($ctime(8/9/2004)).
Using $duration makes the seconds appear as weeks and days.
$duration($calc($ctime(8/9/2004) - $ctime))
I think this is what you need. Note though that it doesn't create two values!
Use it with echo, msg, say, me, describe or any command.
Replace 8/9/2004 with any date (or variable containing one) in the form dd/mm/yyyy.
Try typing:
//echo -a $duration($calc($ctime(8/9/2004) - $ctime))
to see the results.
(I used 8/9 which is a future day from today (2/9) rather than 8/8 which is not...)