plot_date issue : OverflowError: date value out of range

Hi all.

I'm trying to use plot_date and I get an error I don't understand.

I've reduced my problem to this small example:


from pylab import figure, show

dates = [301,302,303]
#dates = [1,2,303]
#dates = [1,2,3]
values = [1,2,4]

fig = figure()
ax = fig.add_subplot(111)
ax.plot_date(dates, values,'-')


This works. I get a plot with the values for the 301st, 302nd and 303rd day
of year one. (I don't actually mind the year, all I know is my simulation
starts the first of january of any year.)

If I use dates = [1,2,303], it works as well.

However, with dates = [1,2,3], it does not, and I get the error :
OverflowError: date value out of range

I don't understand. I may not be aware of everything concerning dates in
python, but as far as I understand, those dates are correct and are the
first three days of year one. Aren't they ?

Since I don't mind the year, I guess I could add an arbitrary number of years
to my dates as a workaround for this error.

Another question that could be related:

Thanks for any help.