I recently timed out my old Oysterquartz with a new battery between May 27 and July 10. Over that 45 day time period it lost 3 seconds (approximately 24s/year). It spent the vast majority of that time sitting at 67 degrees in my safe so I suspect it would do a little better on my wrist.
The watch was purchased new in 1980 and serviced for the first time around April 2011 by Rolex USA.
Not much to brag about by current HAQ standards but not bad for an old OQ.