ploting with dates?

Hello, I am trying to learn how to plot using dates. In my code I'm
basically trying to do the following:

t1 = ['05/05/2005', '05/06/2005', '05/07/2005', '05/08/2005']

t3 = [1,2,3,4]

#plot data
self.axes.plot_date(t1, t3, 'bo')

this doesn't work for me. What does the input for plot_date need to look
like? Thanks.

Jeff