Hi
You can use a Real time clock I2C from Dallas semiconductors (includes
seconds, minutes...years counters, Ram, alarms,etc. all in 8 pins) and the
pic routines for I2C are in the application notes from Microchip.

                               Claudia Ximena Bustamante Osorio
                               Pontificia Universidad Javeriana
                               Ingenieria Electronica
                               Santafe de Bogota,D.C.
                               Colombia
                               E-mail:cxbustam@venus.javeriana.edu.co
                                      cxbustamante@usa.net