Offset Update

[Sabresoft]

On the DST time change earlier this month I reset all my HAQ watches with a deliberate offset that was computed as follows:

Previous Test SPY estimate * 238 / 365 * (-½)

238 comes from the number of days in DST in North America this year. If the watches were to perform exactly as predicted the offset at the fall time change would be the negative of the pre-offset. Of course my initial offset actually achieved wasn't always close to what I had computed.

Below is a table that shows the offset at the time of setting the watch at DST time change, and the predicted and measured offset 20 days later.

[Hans Moleman]

You always seem to find another way to juggle the numbers!
Yet another way to look at them.
Very impressive.

[Sabresoft]

You always seem to find another way to juggle the numbers!
Yet another way to look at them.
Very impressive.

In theory, around July 6 all that watches should be bang on accurate. Should be interesting to see just how close any of them actually get to this target.

[Sabresoft]

Well almost two months since DST setting, and here are the current offset results:

Least accurate is the Precisionist, but all are within at worst 4 seconds of correct time.

[Sabresoft]

I have not been keeping my offset prediction up to date on the frequency that I originally planned. I decided to do it today, and frankly the results are perplexing, with just about all of the offsets (at 124 days) quite different from what I projected. I am not showing the SPY estimates, but while for the Airwolf and C70 they are quite good (better than last test), the others are quite disappointing. The UX is heading for 19 SPY and the Miros for 15 SPY. The (un)Precisionist is heading for a very poor 38 SPY.

[Hans Moleman]

Sorry I forgot, do you keep your watches at a constant temperature?
Can you blame that on temperature changes?
Did you take the leap second into account?

[Sabresoft]

Sorry I forgot, do you keep your watches at a constant temperature?
Can you blame that on temperature changes?
Did you take the leap second into account?

No-Yes-No

It has been very hot of late, but that brings the stored watches pretty much up closer to body temperature so I would expect that the watches wouldn't project such high SPY estimates. Also some are projecting much worse than others. The identical caliber C70 and Miros are showing significantly different behaviour. But I must admit, all (TC) within COSC.

The Precisionist is another story. A lot of people are saying that the Precisionist doesn't live up to its name, but actually precision has nothing to do with the SPY performance of the watch. A watch can be very precise, but be totally inaccurate. Precision has to do with what level of measurement is displayed by the watch (i.e. 1/10's seconds versus seconds). A watch could be extremely precise, say showing on a digital display 1/1000's of seconds, but if that time shown is off by say 2 seconds a day, it has terrible accuracy. On that basis my Precisionist is my most precise analog watch showing 1/5 second markers with its smooth seconds hand, but as it is pointing to the wrong marker (off by at least 25/5's right now), it is the least accurate of my "accuracy" gang (now 9 watches with the recent acquisition of a Casio ProTrek).

This is one reason I suspect that Citizen and Seiko have tended to move their precise offerings from TC to RC. RC has its issues too, but fortunately where I live I am able to get a radio signal on a regular basis. Even on a recent trip to part of the middle east I was able to get a signal from europe. Two of my watches (the Citizens) sync well inside a drawer. The two Casios tend to sync only every few days inside the drawer, but do seem to sync better during daylight hours than the Citizens.

[Sabresoft]

Chart adjusted for leap second (thanks Hans for the heads up).



The SPY values mentioned earlier now go as follows:

- Miros from approx 15 SPY down to 12
- UX from approx 19 SPY down to 16
- Precisionist from approx 38 SPY down to 35

When I get some time I will do a test 1 vs test 2 vs test 3 comparison on the SPY curves for each of the watches.

[Hans Moleman]

I think that if a watch is regulated perfectly, it is regulated for 30℃ (86℉).

30℃ is the temperature of a watch being worn. I was surprised about that too, but it does not get to body temperature. Dwjquest did some measurements earlier.

I don't know how hot it is right now, but might it be hotter than that?

That's the great thing about your measurements. It shows the responses of all watches to the same environment.

[Sabresoft]

We've been experiencing temperatures in the 27 to 33 C range. The indoor temperatures in the bedroom have been staying quite high, even overnight despite some overnight cooling outdoors.