[Zope] Representing dates before 1970 in DateTime

I have written a CV product for Zope. Basically it contains a list of competencies. Each competency has a start and end date. I have used Zopes DateTime object for this, and that is the problem, as it will only go back to 1970. But some of the users has educations and jobs from before 1970, so I also need to represent dates before 1970. Is there a simple workaround for this, or do I need to use something like mxDateTime for the task? regards Max M