My Rolex is 20 seconds slow per day.

[solcris]

I just inherited a 1991 Ladies Rolex. I seems to run 20 seconds slow per day while on the watch winder. My wife doesn't wear it much so most of the time it's on the winder. From prior posts I see that 20 seconds per day seems excessive. Will a Rolex service bring it back to acceptable standards.
Any other suggestions welcomed.