Given some of the discussions here about using power-line frequency for a time signal, I though this might interest some folks.
A yearlong experiment with the nation's electric grid could mess up traffic lights, security systems and some computers — and make plug-in clocks and appliances like programmable coffeemakers run up to 20 minutes fast.
"A lot of people are going to have things break and they're not going to know why," said Demetrios Matsakis, head of the time service department at the U.S. Naval Observatory, one of two official timekeeping agencies in the federal government.
I haven't any idea whether the alarm clock in the bedroom uses line frequency. Not sure there's any way to find out either. Not sure whether this is a nudge to get me to play with building an Arduino alarm clock. It'd be fun though.