A real, completely mechanical watch? No battery or crystal? I'm sure my Seiko isn't be best there is and maybe it could be improved with servicing, but I think electronics have given people unreasonable expectations of accuracy
No, the people responding to you are correct: even the crummiest mechanical watches should not drift by more than 10-15 seconds/day. COSC certification, which most nice mechanical watches have, requires no more than 2 minutes/month (4 seconds/day) of drift, and most do even better than that, 1-2 seconds/day is normal.
If your Seiko is really drifting by minutes per day, something's badly wrong with it and you should get it serviced.
