In [5]:
df['OrderDate'].head()
Out[5]:
0   2009-01-11
1   2009-01-20
2   2009-02-03
3   2009-02-06
4   2009-02-06
Name: OrderDate, dtype: datetime64[ns]
In [6]:
df['OrderDate'].dtype
Out[6]:
dtype('<M8[ns]')