Quartz watches gaining time

[spoilsofwar01]

I have 3 Casio (work / Banger) watches that I've owned for over 30 years, in the uk we have Daylight Saving Time which means we advance time by 1 hour, so twice a year I have to reset my quartz watches.

I used the Rolex forum clock to set the time on all 3 but on this occasion I noted a difference in the time on all of them, none were correct,

ruling out low power in the batteries I got to wonder what if at all would cause this? all I could find on the internet was the following that didn't offer up any explanation.

Time-keeping of a quartz watch is based on the crystal oscillator of high frequency (32,768 Hz). ... As a result, you can use a quartz watch for a long time without worrying about loss or gain. Please note that the analogue quartz and combination quartz watches with built-in step motors are affected by magnetism

I reset all and will monitor them all to see if there's an immediate change in the time......

[trfChris]

How much were the watches off by? My 20 year old Casio is around 0.8s/day fast which is worse than my Rolex!

[Andad]

The clock on the Forum takes its time from your computer.

[DoraTheExplorerII]

Originally Posted by trfChris

How much were the watches off by? My 20 year old Casio is around 0.8s/day fast which is worse than my Rolex!

Ha my Casio that was straight from Amazon was way worse than my 8 year old Rolex, which was only +/-2 or 1, something like that.

[spoilsofwar01]

adding to this my 1980's Sanyo clock radio is also off by a minute...... arrrrggghhh something else to plague my head...not that im OCD about these things, so much for Quartz accuracy.

[trfChris]

Originally Posted by spoilsofwar01

adding to this my 1980's Sanyo clock radio is also off by a minute...... arrrrggghhh something else to plague my head...not that im OCD about these things, so much for Quartz accuracy.

To follow up on this, normally quartz watches are not super accurate (around 5-15s/month is not uncommon). For instance the quartz clock in your iPhone & Apple Watch is not particularly accurate. The reason your iPhone clock always show the correct time is that they are reset several times per day over the internet to match the time of this atomic clock:

https://en.wikipedia.org/wiki/NIST-F1?wprov=sfti1

This clock is VERY accurate, rated to around +-1 second per 100 million years!

There is a specific class of very accurate quartz watches, called High Accuracy Quartz (HAQ). Most of these are around 10s per year, I believe the most accurate is around 1s per year.

Here is a good Hodinkee article about HAQ watches:

https://www.hodinkee.com/articles/th...ter-ab9000-61e

[spoilsofwar01]

Originally Posted by trfChris

To follow up on this, normally quartz watches are not super accurate (around 5-15s/month is not uncommon). For instance the quartz clock in your iPhone & Apple Watch is not particularly accurate. The reason your iPhone clock always show the correct time is that they are reset several times per day over the internet to match the time of this atomic clock:

https://en.wikipedia.org/wiki/NIST-F1?wprov=sfti1

This clock is VERY accurate, rated to around +-1 second per 100 million years!

There is a specific class of very accurate quartz watches, called High Accuracy Quartz (HAQ). Most of these are around 10s per year, I believe the most accurate is around 1s per year.

Here is a good Hodinkee article about HAQ watches:

https://www.hodinkee.com/articles/th...ter-ab9000-61e

Hello Chris, many thanks for the information, it just goes to show that you live and learn, once again many thanks, "H"