[notatoad]

Again, I'm not trying to suggest anybody made a wrong choice here, just that they made an intentional decision.

Theres no way this is happening because somebody called math.round() without thinking, you don't round time and the developers who make apple's clock app know that. They made a conscious decision to have the timer work this way. You can disagree with whether they made the right choice, but I'm pretty sure they thought about it.