India, June 29 -- We don't think of them as a luxury exactly, those few extra moments of sleep after one hits snooze on an alarm. But that's really what they are. Through most of history, it was impossible to set a personalised wake-up call, unless one were royalty or nobility. Before we get to how alarms have worked, through the centuries, have you ever wondered why the default snooze duration is nine minutes? Do you secretly think it's because the phone manufacturer is trying to help you cheat, and knows 10 would simply be too much? It isn't that; well, not exactly. Long before smartphones, the snooze feature existed in mechanical timepieces. Because of the way their gears were designed, it was nearly impossible to allow exactly 10 minute...