1618 Alhambra Blvd Sacramento, CA 95816. Phone: (916) 227-6503. Hours of Operation: Mon-Fri 8:30am-5:45pm Sat 9:00am-5:00pm Sun closed. *The USPS does. Zip code 95813, Sacramento Post Office, 2000 Royal Oaks Dr, CA — hours of operation, phone number and location on the map. Opening Hours of USPS Post Office Sacramento, 2000 Royal Oaks Dr, Sacramento, CA 95813-9998.