If you enable GCC’s -ftrapv option, the subtraction overflow triggers an abort. Alexander’s patch works around the problem for asctime(), but the problem still exists in other cases, such as:

>>> time.mktime((-2**31 + 1899, *(0,) * 8))
Aborted (core dumped)
[Exit 134]

Attaching a version of the patch without the conflicting whitespace changes.

Why does Python even need to support such extreme time values? It would seem much simpler to raise an exception.