OK.
2004 CMax 2.0TDCi Zetec. Radio/CD is Ford 6000CD
You need to be on the FM wavelength (so that the RDS time signal can be picked up). This is important because if you are on MW the RDS time option is not on the menu.
Press and hold the Menu button for a few seconds to get the second menu set.
Press Menu button to scroll through the following items:
TA >> AF >> Vehicle ID >> Clip Detect >> Clock 24/12hr >> RDS Time On/Off
Hope this helps. I have always found setting the radio a bit of a black art.