I agree. I'd specify this by saying:
o An empty string sent from a browser for an optional_date field is interpreted as a null (not specified) value
o The "internal" representation of an optional_date (the value you find in the REQUEST after conversion) is always either a valid DateTime instance or None
I think then the value in the fields will be shown as "None", which I don't particularily like, even though I would rather have None as the internal representation instead of an empty string. Is there a way to fix that, so that date_fields set to None will be displayed as empty?
Sure. The property forms just need to do the equivalent of: <dtml-if theDate> <dtml-var theDate fmt="somthing"> </dtml-if> I know that this is a style issue to some, but I feel that the value should either be null or valid, and code and templates should be written to deal with the two possibilities as a matter of course. Brian Lloyd brian@zope.com V.P. Engineering 540.361.1716 Zope Corporation http://www.zope.com