**All Automatic Watch will gain / lose time:-
All automatic watch including a Rolex will gain or lose time when they are new or not worn on the wrist all the time.
According to Seiko Corporation, the timekeeping accuracy of the 7S26/7S36 movement is +-15 s/day. It has been known that this movement typically runs fast for a few weeks when fresh from the factory sometime get as far as +45 to -35 s/day. Also it keeps better time when worn on the wrist all the time. If you're not wearing the watch for more than its 42 hour reserve, you'll have to rotate it to keep it going or reset the date/time. The watch will "settle down" to a more reasonable accuracy level after being worn for a couple of months.

If your watch loses or gains a few seconds per day, you can take it off at night and :-
 1. Lay the watch flat with the dial uppermost (To gain a few seconds if it is slow).
 2. Lay the watch vertically with the winding-button downwards. (To lose a few secs)
 3. Lay the watch vertically with the winding-button uppermost. (To lose more secs)
(This is reproduced from Rolex instruction manual)