When did "snooze" become 6 minutes?

When I was a kid, the "snooze" alarm on every clock would cause the alarm to go off again 9 minutes later. Seemed an arbitrary figure, but it also seemed to work -- often, 9 minutes later, I'd feel more refreshed.

Now every clock I or my wife have that has a snooze on it -- the snooze is 6 minutes. Even my cel phone's alarm snooze is 6 minutes. And contrary to 9 minutes, 6 leaves me feeling less refreshed.

So what's up with that? Is our society in such a rush that 3 extra minutes means death?