NavList:

I am not sure what effect will lightning strike may have on a quartz watch, probably it depends on how close the lightning strikes. (A direct hit will destroy a mechanical watch as well).

Speaking of the rating, I have some experience with rating of mechanical watches. Modern mechanical watches with Swiss movement are pretty good, their non-uniformity is supposed to be 2-4 sec per day. So if you compare it with time signals every day (while electronics works), you can trust them for several days after the lightning strikes. My own watch (Tissot, which costs about $300) in the long trial never changed its rate by more than 2 sec per day. But after long time, it can certainly go off substantially.

I also have an (old, Soviet) marine chronometer. Chronometer can have a rate of more than 2 seconds per day, but its great advantage in comparison with watch is that this rate is CONSTANT. So I know about this rate, can measure it, and can make correction, and in this way I can keep the correct time for long time. (The watch can deviate one day by +1s another day by -2, and this is unpredictable. So it does not keep correct time for long periods, no matter what correction you make).

You can improve performance of a wristwatch if you don't wear it, but keep in the same position, for example "face up". The main problem with mechanical watch is not to forget to wind it every day, at the same time. This also applies to chronometer. If your watch is automatic, it is still better to let it lay down in a box and wind every day than to wear it on your wrist.

Alex.