[Zope] Need help with date comparisons

Hi all again. I have a blank in my mind where I hoped the answer might be to this probably straightforward exercise. I have a zclass containing a date property called event_date. I want a page that loops through the months of the year, starting with the current month, and in each loop displays all the instances from the catalog with an event_date within the month in question. I just get stuck, completely stuck, trying to get the month value from the event_date and to compare it with the current month value. Anyone done this or something like this? Is this hard or am I a bit, you know, dense? thanks Jonathan