For example:

E:\>py -3.6 -c "import datetime; datetime.datetime.fromtimestamp(42)"
Traceback (most recent call last):
  File "<string>", line 1, in <module>
OSError: [Errno 22] Invalid argument

Works fine at least with Python 2.6-2.7 and 3.3-3.5. Only tested on Windows (missing deadsnakes for easy Linux testing).

I was also surprised to get OSError in general, but apparently fromtimestamp uses that instead of ValueError nowadays in some error situations.