Does anyone manufacture a quartz watch in which the speed can be adjusted?
I have $11 Casio digital watch which I have observed weekly for the past three months. I then ran the 12 observations through a linear regression which showed that the watch gained four seconds every week. While the watch is now 53 seconds in error, the error is extremely consistent. If I could get the watch to pause for 24 milliseconds every hour, all 12 observations would have been within one second of the correct time. (Note: 11 of the 12 observations would have been within one quarter second of the correct time, so it may have been the observation itself that was in error.)