[Zope] calling a value?

I have a very strange problem, that probably stems from me being new to python I have a script that does this now = DateTime() session_id = now.millis() # write to DB with session_id # set cookie with session_id the problem is that it seems that session_id holds an instance to now.millis(), because the session_id value in the database is a few milliseconds earlier than the session_id value stored in the cookie. It seems to me that referencing session_id *calls* now.millis() and passes that value to the db and cookie methods. Is that possible? Is that what's happening? I just want a long int out of millis() (I tried casting it six ways from sunday too - no luck) -jim