df = DataFrame(dict(date=date_range('20130101', periods=10)))
df
df['date'] + timedelta(hours=2) - datetime.datetime(1970, 1, 1)
(df['date'] + timedelta(hours=2) - datetime.datetime(1970, 1, 1)
    ) / np.timedelta64(1, 's')
Python Pandas Series of Datetimes to Seconds Since the Epoch