I'm creating a brand new ZClass (called "PDFClass"). It's my first ZClass. I've just added the Common Instance Property Sheet (called "PDFProperties"). Now I'm trying to add properties to that property sheet. I added one "string" property OK, but now when I add the "date" property "pub_date", I get this error: Zope Error Zope has encountered an error while publishing this resource. Invalid Date-Time String Sorry, a Zope error occurred. Traceback (innermost last): File /opt/Zope-2.0.0/lib/python/ZPublisher/Publish.py, line 214, in publish_module File /opt/Zope-2.0.0/lib/python/ZPublisher/Publish.py, line 179, in publish File /opt/Zope-2.0.0/lib/python/Zope/__init__.py, line 201, in zpublisher_exception_hook (Object: PDFProperties) File /opt/Zope-2.0.0/lib/python/ZPublisher/Publish.py, line 165, in publish File /opt/Zope-2.0.0/lib/python/ZPublisher/mapply.py, line 160, in mapply (Object: manage_addProperty) File /opt/Zope-2.0.0/lib/python/ZPublisher/Publish.py, line 102, in call_object (Object: manage_addProperty) File /opt/Zope-2.0.0/lib/python/OFS/PropertySheets.py, line 403, in manage_addProperty (Object: PDFProperties) File /opt/Zope-2.0.0/lib/python/ZPublisher/Converters.py, line 157, in field2date File /opt/Zope-2.0.0/lib/python/DateTime/DateTime.py, line 499, in __init__ Invalid Date-Time String: Sorry, an error occurred Of course, the value is invalid -- I didn't put any value in the "Value" box, because this is a class property, and values only make sense when the class is instantiated, right? Is this Zope's problem or mine? -- Thanks -- Loren