You need to pass the delta in as a kwarg:

https://docs.python.org/3/library/unittest.html#unittest.TestCase.assertAlmostEqual

>>> unittest.TestCase().assertAlmostEqual( datetime.date(2020,1,5),  datetime.date(2020,1,2), delta=datetime.timedelta(2))
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "C:\Users\User\src\cpython\lib\unittest\case.py", line 893, in assertAlmostEqual
    raise self.failureException(msg)
AssertionError: datetime.date(2020, 1, 5) != datetime.date(2020, 1, 2) within datetime.timedelta(days=2) delta (datetime.timedelta(days=3) difference)
>>> unittest.TestCase().assertAlmostEqual( datetime.date(2020,1,5),  datetime.date(2020,1,2), delta=datetime.timedelta(3))
>>>