2016-12-31 23:59:50
2017-01-01 00:00:10
Unix time differs by 20 seconds (assuming the system/library doesn't use smearing). But actually elapsed time is 21 seconds, since 2016-12-31 23:59:60
was the last added leap second. This timestamp cannot be represented by Unix time (again assuming no smearing, with smearing you could). a = b = random.random()
a += 1
a == b # False
Only because floats are immutable and thus an implicit copy is made and lists are mutable so the same mutable instance is pointed to by both names.
That must be the worst explanation of complex numbers I ever read. It's not even remotely connected.