Trying to get a Zope DateTime object (as dictionary value) via xml-rpc gives on OverflowError! You can try it yourself: (I used a freshly installed Zope-2.9.3 [with python-2.4.3] on Linux FC3; but other versions should behave equally.) Add a Python Script in the Zope OFS root folder: return {'root_modification_time': container.bobobase_modification_time()} The www request returns: {'root_modification_time': DateTime('2006/05/13 14:33:12.445 GMT+2')} But the XML-RPC returns: xmlrpclib.Fault: (-1, 'Unexpected Zope exception: exceptions.OverflowError - long int exceeds XML-RPC limits' The reason for this is, that the DateTime object is treated as a normal instance by xmlrpclib, ie __dict__ is marshalled (which, unfortunately, contains the attribute '_millis', which is usually too big). It would be better anyway, if Zope DateTime objects would be marshalled as XML-RPC dates (dateTime.iso8601). Eg like that: --- xmlrpclib.py.ori 2006-05-13 13:29:45.606954800 +0200 +++ xmlrpclib.py.wlang 2006-05-13 13:32:45.923542512 +0200 @@ -701,10 +701,15 @@ def dump_instance(self, value, write): # check for special wrappers + import DateTime as ZopeDateTime if value.__class__ in WRAPPERS: self.write = write value.encode(self) del self.write + elif value.__class__ == ZopeDateTime.DateTime: + self.write = write + DateTime(value).encode(self) + del self.write else: # store instance attributes as a struct (really?) self.dump_struct(value.__dict__, write) However, this would modify xmlrpclib.py from the python distribution, wich is plain ugly. Can anyone think of a better solution? Is it possible to change xmlrpclib.WRAPPERS from Zope, but leave python's xmlrpclib.py unaffected? \wlang{} -- Willi.Langenberger@wu-wien.ac.at Fax: +43/1/31336/9207 Zentrum fuer Informatikdienste, Wirtschaftsuniversitaet Wien, Austria