pd.to_datetime(df.column)
import pandas as pd
#create DataFrame
df = pd.DataFrame({'stamps': pd.date_range(start='2020-01-01 12:00:00',
periods=6,
freq='H'),
'sales': [11, 14, 25, 31, 34, 35]})
#convert column of timestamps to datetimes
df.stamps = df.stamps.apply(lambda x: x.date())
#view DataFrame
df
stamps sales
0 2020-01-01 11
1 2020-01-01 14
2 2020-01-01 25
3 2020-01-01 31
4 2020-01-01 34
5 2020-01-01 35