I want to call the man who invented the snooze button
every nine minutes for the rest of his life.
"What?" he'll say. "What is it? What do you want?"
"Nothing," I'll say. "I'll tell you later."
--John Erhardt
- - -
Ever wonder why most snooze buttons are set to silence the alarm for 9 minutes instead of another, more psychologically appealing (that is, rounder) number? Turns out the answer has very little to do with psychology and has all to do with Switzerland. Maybe not Switzerland, but clockmakers. One can't be a clockmaker if one isn't Swiss, right?
Back when clocks actually had gears, every single cog, spring and wheel within a timepiece was standardized so that parts could be easily swapped from clock to clock in order to facilitate repairs. The invention of the snooze button threw a wrench into the works of clock design - due to the sizes of the available gears the only times physically possible for the snooze to function at were slightly under 10 minutes or slightly over it - 10 minutes on the nose wasn't doable. It was assumed that the first choice was more appealing (read: marketable) and the time was set at 9-something.
With the advent of electronic clocks, 9 minutes and change became 9 minutes exactly. It was what people were used to and seemed easiest to just chop off the extra seconds.
Sources:
http://www.straightdope.com/classics/a991126.html
http://foolong.org/archives/2003/08/22/snoozing.html