Why do Quartz Clocks Drift?

When you buy a clock to put on your wall at home, it’s safe to assume that if that clock is running a few seconds or even minutes fast or slow, it’s not going to make a big impact on your day. But, if you are part of an organization that relies on accurate scheduling, like in a school, hospital, or manufacturing facility, inaccurate clocks can create some major headaches.

The Science Behind a Clock's Moving Hands 

While it may be slight, most clocks are either losing or gaining time throughout the day. If your clocks aren’t part of a synchronized system, they will inevitably drift from the true time and vary from room to room.

Quartz, the mineral found in most clocks, is responsible for keeping time in your devices, but it’s also at the heart of why clocks drift. “Quartz has a unique characteristic, that if you supply it with an electrical pulse, it’s going to vibrate at 32,768 times per second,” says George Wilkes, president of American Time. “The clocks measure these vibrations and advance the hands after every round of oscillation.” A crystal oscillator is a type of electronic oscillator. In this type of oscillator, the crystal acts as a resonator, and its vibrations determine the oscillation frequency.

However, quartz has its flaws. “It’s not perfect, small things like temperature variations can impact the clock and how frequent the quartz vibrates,” he says.

Synchronization Saves the Day

“Quartz should be able to keep time to within one second a day,” says George. However, that one second either direction can add up to inaccurate time if it is not corrected with a synchronized clock system.

“A synchronized system doesn’t stop the clocks from drifting, it corrects them at multiple points throughout the day,” says George. “The clock operates by itself, but also works with a master that is getting it’s time from a centralized system to correct itself at the same frequency of all the clocks in the system. That way, they all remain in sync with each other.”

This is most useful in facilities with dozens of clocks, where time is of the essence. In these places, the alternative to a synchronized system is a lot of extra legwork for staff who has to adjust the clocks manually.

“For example, if you go to a big box store and buy 100 clocks for your school, I guarantee your maintenance staff will spend time over the next years going around from classroom to classroom adjusting clocks, and that's not ideal,” George says.

It seems like a no-brainer to us. Why waste time manually adjusting each clock when you can have a system that automatically does it for you? That way, you can spend time on more pressing issues.