this is an update on my previous review
I synchronized my Citizen with my Casio G-Shock Atomic Watch on July 1. The Casio self adjusts its' time every day by setting itself to the atomic clock in Colorado and is accurate to the second, well it is now Sept. 7, more than 2 months (since July and Aug have 31 days I didn't ever have to unscrew the crown to readjust the date...which is pretty hard to see anyway) and the Citizen is still within 1 second of the atomic clock! That is as accurate as a non atomic watch can be, judging from that I would assume the watch to be accurate to within a few seconds per year. Also, I have taken it diving several times and it is an excellent dive watch, even though as scuba divers know, a dive watch is not the same as in Mike Nelson's day, since we have dive computers that keep track of time and depth and dive tables for you. But, I think that if he were diving today, Mike Nelson would be very happy with this functional dive watch!