Had the same problem until we doped out that by pressing the volume button, a menu canme up on the display. When we got to "clock" we hit "Scan" to up the hours and "Seek" for the minutes. Dunno how we ever figured it out without the manual, but now it's old hat as it seems to work on many other car radios. Still, the companies' big problem is that they don't make this stuff intuitive any more.
Dang, we’ll have to try that! This is a radio that you turn on by pressing “source,” although at least it’s got an Off button. It came with the used car.