[Zope] newbie: comparing dates?

[Georg Rellensmann]

Hi all,

another newbie-question:

- I created a zclass with three date properties.

- Now IŽd like to display the most recent of these dates in
  directory-listings etc.

QUESTION 1: How do I compare dates in dtml code?

QUESTION 2: How do I exclude empty values from processing?
         (I installed raptoŽs null date-patch, seemed to work
         fine; for that patch see:
         http://www.zope.org/Members/rapto/nullDate?pp=1)

regards, -georg.rellensmann-