>>> df = session.create_dataframe(['2013-05-17', '2013-05-17'], schema=['a'])
>>> df.select(to_date(col('a')).as_('ans')).collect()
[Row(ANS=datetime.date(2013, 5, 17)), Row(ANS=datetime.date(2013, 5, 17))]
>>> df = session.create_dataframe(['31536000000000', '71536004000000'], schema=['a'])
>>> df.select(to_date(col('a')).as_('ans')).collect()
[Row(ANS=datetime.date(1971, 1, 1)), Row(ANS=datetime.date(1972, 4, 7))]