Wow! It just goes to show that ANY hobby or interest can be taken to the "nth" degree!Just in case you don't have enough things to obsess over and be anal retentive about, let me introduce you to a website called Time.is - exact time, any time zone. It serves a similar purpose as the http://nist.time.gov website, but I suggested to the author of time.is that he add the ability to do tenths of a second on his site for those of us that are freaks about precise watch synchronization.
To enable tenths on time.is:
When time.is first loads it's going to stutter a bit as the ads load. On my Android phone I have an ad blocker that prevents this, but on my PC even AdBlock doesn't prevent the initial stutter. It stabilizes after about 15 seconds.
- Click the hamburger icon (3 horizontal lines) in the upper right corner
- Choose Customize
- Click the checkbox for "Turn seconds, tenths and milliseconds on/off by clicking the right side of the clock"
- Click "Back to the Front Page"
- Click in a blank space to the right of the time display to switch between whole seconds, tenths, and thousandths.
Most of your watches appear to be quartz so they should hold to around 15 seconds a month if they aren't radio-sync. If they are radio-sync and you get a good sync each night then they'll probably never be off by more than a half a second.
Most of my watches are mechanical which means I check the sync each day when I pick which watch I'm going to wear. If it's a Spring Drive it'll gain around 18 hundredths of a second a day. If it's a lower end mechanical it'll probably gain around 5 to 10 seconds in a day. Higher end mechanicals tend to be around 1 or 2 seconds a day.
I also have a couple "HAQ" (High Accuracy Quartz) watches that only gain about 5 seconds a year, about 1.4 hundredths of a second per day, with no external syncing. That's a pretty incredible feat of engineering in my book - worthy of wearing even though it's quartz (I generally eschew quartz, with limited exceptions).
I'm such a time-nerd that I even have a live-data GPS clock on top of my dresser with the watch box, which displays tenths of a second and should never deviate from atomic clock time by more than one ten-thousandth of a second. In reality you might not even say it's a clock because it doesn't actually keep the time - it displays the time live from the GPS signals in real time. So if it loses GPS lock it won't display the time. If it's showing the time, it's definitely correct. This is different than the radio sync clocks which only usually sync the time once in the early morning hours and then use their own internal timekeeping for the next 24 hours until the next sync. Radio sync clocks with typical quartz timekeeping will gain or lose around a half a second during the course of the 24 hours that elapse between syncs.
Now a half second may not seem like much, but if you're a time lord and checking the accuracy of a very expensive timepiece that is supposed to be very accurate, your clock being off by a half second could lead you to believe that there is something REALLY wrong with your watch when there isn't. Yeah, some of us are that nuts about this stuff. But you might have deduced that obsessiveness when I said my Spring Drive gains "about 18 hundredths of a second a day". In fact the actual measurement was 0.187 seconds per day - and if you had a half-second error in your reference time source it would really screw up your testing unless you were testing over a long enough period to make that half-second irrelevant.
I have compared the time.is time against live GPS time and find that it is very consistent. I frequently use time.is for doing a quick rough sync of a timepiece, when I don't need it to be flawlessly synchronized (i.e. I'm not doing a timing analysis of the piece).
Interesting, for sure. But, will I be doing that? Not, yet! LOL!
My only mechanical watches are the Rolex and Breitling... both not working at this time.