## The Snooze Button

Why is it very common to have a 9 minute snooze interval on alarm clocks, why not 10 instead?

By setting the snooze time to 9 minutes, the alarm clock only needs to watch the last digit of the time. So, if you hit snooze at 6.45, the alarm goes off again when the last digit equals 4. They couldn’t make it 10 minutes, otherwise the alarm would go off right away, or it would take more circuitry.

Posted in Brain Teasers

6 Comments on "The Snooze Button"

Keesh says
October 20, 2015 @ 11:41

A clock

fivebee says
January 20, 2016 @ 11:24

Umm… That has nothing to do with the riddles.

Miranda says
April 12, 2016 @ 10:00

I’m confused

It is a very weird explanation especially since my alarm (along with a lot of modern clocks) has a 5- and a 10-minute interval.

Computer Scientist says
October 13, 2018 @ 06:18

This is not at all how digital clocks are built, and has no basis in reality. Electronics are not done in base 10 numbers, base 2 or base 8 (dip switches). I’ve never seen a clock built like this, and my clock snoozes for 7 minutes, not 9

nova says
October 15, 2021 @ 17:59

but you could just watch the 10 place for the numbers and have less circuitry.