Seiko Movement V172 Used As A GMT and Calibration

One reason I bought the Seiko SBPY119 is there is a hidden feature behind the alarm clock – you can actually use it as a GMT if you don’t need an alarm.

Last week my “GMT” was running 2 minutes behind. It was probably hit hard by my baby. That triggered me to relearn how to calibrate to fix the error and how to make it a GMT in the first place.

The trick is in the calibration. Basically the way alarm clock works is you have to tell the watch that the main clock and alarm clock were pointing to a same time. They have to share a starting point first before you can move the alarm clock to a different time. This is the calibration process.

To use it as a GMT, you have to deliberately make a mistake. You need to trick the watch into thinking the main clock and alarm clock are in sync and sharing the same baseline. But actually they are not. Actually you are setting the alarm clock to a different timezone.

When you pulled the crown all the way out, you can press and hold the top right chronograph start button for 2 seconds. This will cycle through the baseline adjustment for chronograph minutes, chronograph seconds and then the alarm clock (wait for the clock to finish spinning a full cycle). When it is cycled to the alarm clock, set the GMT time. Then turn the crown to set the correct local time on the main clock. Push the crown all the way in when finished. This will trick the watch into thinking the alarm clock and main clock are now pointing to a same starting time. Alarm will not be activated.

Obviously this works for all V172 movement watches.