Why doesn't this work?

[Ron Garret]

Python 2.3.5 (#1, Jan 30 2006, 13:30:29) 
[GCC 3.3 20030304 (Apple Computer, Inc. build 1819)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> from datetime import datetime
>>> class ts(datetime):
...   def __init__(self): pass
... 
>>> ts()
Traceback (most recent call last):
  File "<stdin>", line 1, in ?
TypeError: function takes at least 3 arguments (0 given)
>>>