Previously accurate Seiko dive watch suddenly gaining 1-2 hrs/day

Main cause would be that the date gear teeth have been stripped. This is done by setting the date whilst the hands are trying to change the date themselves (between 10pm and 2am). Always adjust the date with the hands around 6.0clock. You will need to return your watch to where you bought it for repair I'm afraid.

Interesting question. I know little about watches but, as you would know, your watch does have a quartz movement, so, from Wikipedia, 'Quartz clock':

Standard-quality resonators of this type are warranted to have a long-term accuracy of about 6 parts per million at 31 degrees C (87.8 F): that is, a typical quartz wristwatch will gain or lose 15 seconds per 30 days (within a normal temperature range of 5 deg C / 41 F to 35 deg C / 95 F) or less than a half second clock drift per day when worn near the body.

If a quartz wristwatch is "rated" by measuring its timekeeping characteristics against an atomic clock's time broadcast, to determine how much time the watch gains or loses per day, and adjustments are made to the circuitry to "regulate" the timekeeping, then the corrected time will easily be accurate within 10 seconds per year. This is more than adequate to perform celestial navigation.

Assuming that you have a computer with internet-synced time and good internet, meaning around 1/100 second accuracy, why not compare the watch to the computer over the space of a week?

Thank you for contacting FixYa.
I would contact Omega on this issue at this link:
http://www.omegawatches.com/customer-service

Best regards. Jewel

Hi honestfunguy. Take it back! Omega watches are usually guaranteed for 2 years or even 3 years (Co-axial escapement), so you should not have a problem getting it repaired under warrantee. No way should it be be gaining (or losing) 10 minutes per day, let alone 10 minutes per hour. Could be any number of things, from a broken mainspring to problems with the timing regulator, but they are very complex watches and should not be looked at by anyone apart from Omega whilst in warrantee, otherwise you'll probably void the warrantee. Hope this helps; Eagle58

Hi mtrahan99. My advice is to take it back and get it replaced, particularly if you have only had it a few days. If they won't exchange it or refund you, get a repair under the guarantee. Automatic watches (and Seiko actually make some very good ones) don't need to be worn all the time to wind them, and the fact that it ran so fast and has now stopped would indicate something major like problems with the mainspring. Return it! Hope this helps; Eagle58

dont do anything!the watch needs service.perhaps somehow the watch fallen in a hard surface and something moved or broke in the balance wheel.the hairspring the pallet or the wheel have serious damage.to have your watch healthy wateresistance and accurate try to find a seiko authorized service center to repair your watch!

if your caliber is automatic 7s26b something is wrong with the hair spring try a seiko service center anyway isnt something that you can fix by yourself!beware!far away from jewelers and local battery changers and other monkey magicians!automatic watch calibers are delicate and they ruine them!

unthread the crown winding,the crown is threaded,first you do pull the crown half not full,for day and date adjusment..second pull full is hour and minutes setting,thats it,.when setting is done, push while winding the crown so it lock..rate me as fixya..

Yes it can be regulated,there is a regulator inside,positive and negative,positive it means make it fast, ,negative it means make its slow..the degree of accuracy of automatic watches is continouos moving, if you don't take it in your wrist,because automatic watch it depends in you,when you are moving ...

it is ok for a new watch to gain or lose more seconds. it takes time for the movement to settle down.