Build the Most Accurate DIY Quartz Clock Yet

Accurate timing is something that’s always been of interest to me. These days we rely heavily on time delivered to us over the Internet, through radio waves from GPS satellites, or broadcast stations. But I wanted a clock that would keep excellent time without relying on the outside world—certainly something better than the time provided by the quartz crystal oscillator used in your typical digital clock or microcontroller, which can drift by about 1.7 seconds per day, or over 10 minutes in the course of a year.