if you break these with a newline you can probably get rid of test_date_1. 

For example

    stat1 = factory.make_user_bookmark_count(
        username=u'admin',
        data=30,
        tstamp=datetime(2013, 11, 15, 4, 4, 4)
    )

Then just return all of stat objects vs juts the timestamps. . You'll need access to both the tstamp, the username, and the data.