.astype datetime
import pandas as pd
# Dataframe example
df = pd.DataFrame({'date':['1995-05-09','1995-05-10','1995-05-11','1995-05-13'],'col_B':[9,7,4,3], 'col_C':[5,1,4,9]})
#This has been answered in the comments where it was noted that the following works:
df.astype({'date': 'datetime64[ns]'})
#In addition, you can set the dtype when reading in the data:
pd.read_csv('path/file.csv', parse_dates=['date'])
Gabriel Juri