I am not entirely sure what you mean by a rock piercing, perhaps you mean a rook piercing, if the piercing is in your ear. Typically, most piercings take between 6-8 weeks to heal completely, though I am sure that some would require more time. If you are unsure of the healing time, contact your piercer for more information.
Healing time is usually from 2-3 weeks but can be more. Your piercer should have already told you what to expect in terms of healing and also care. If not, you can always call the shop and they should be able to tell you. But the general healing time of most piercing is 2-3 weeks.
healing time depends, of course, on what you had pierced. It could be a matter of days, or it might be a matter of months if it's a location susceptible to tearing. Have you considered a long vacation?