Randomizing the hash of datetime objects was first proposed in https://bugs.python.org/issue13703#msg151796.

For the same reasons as str and bytes are non-deterministically hashed in in PEP 456, shouldn't numerics, datetime objects, and tuples be non-deterministically hashed as well? This is for the reason that they can all be used as dictionary keys (additionally, hash(n) begins to repeat when n is a large enough number) -- so it seems like they are also susceptible to the hash collision DoS attacks.