If you have the Ford Audio Guide ,( the handbook that originally came with the car , then it says that the clock+date displays are activated by tuning to an RDS broadcast station (Radio Data System) and cannot be altered or adjusted....so presumably your local RDS station is putting out the wrong time?
Perhaps you could try tuning the radio again to another station to see if that changes it....or just use the normal Ford digital clock on the dashboard and ignore the radio?
RegWorts, June 2008