My second Seiko Quartz. About 18 years old and still quite accurate, but not as good as the first one, which was a little older when I finally had to replace it.
I bought it on a sudden whim, having intended to buy an Omega "tuning fork" watch, accurate to 2 seconds/day which was remarkable at that time, then noticed in the Jewelers window, this brand new technology "quartz crystal" Japanese watch.
I'd heard of the technology on programmes like "Tomorrow's World", but it was expensive. Then suddenly here in the window was a watch, cheaper than the Omega and guaranteed to be accurate to 1/2 second per day.
I bought it, fully expecting the claim to be exagerated, and was prepared to come back the next day for a refund if the 1/2 second had been exceeded.
I checked day after day after day , and eventually after several months, it was a whole second out. At this point the international keepers of time decreed a "leap second" to resynchronize the clocks with the planet, and "lo and behold" it was spot on again, so all along, it hadn't been my watch that was wrong, it was the planet !