[Zope] date: Are month and day required?

[Kyler B. Laird]

We just ran into some strange behavior with
date properties.  Although hour, minute,
second, timezone, ... are not required, day
and month seem to be.

Is there a way to specify only the year or
only the year and month?  (The ZQR was
referenced, but I didn't find info there.)

Thank you.

--kyler