>>> from datetime import *

>>> datetime(2010, 1, 1) < date(2010, 1, 1)

Traceback (most recent call last):

  File "<stdin>", line 1, in <module>

TypeError: can't compare datetime.datetime to datetime.date

but I would expect date(2010, 1, 1) < np.datetime64('2011-01-01') to return False.