fix date in Python code to match output in docs

[jepler]

@thomas-touhey I ran this example and found a small error, just fyi

[jepler]

any way we can share the documentation python files & expected results with the testing infrastructure, so that we verify the expected output is the case?

[thomas-touhey]

Oops, my bad, must've changed it to check if it was working and was not a fluke and forgot to change it back.

sphinx.ext.doctest may answer this need, although it must be said I've never tried it before o_o