I think, cant fully remember, but press the 'D' button, the furthest to the right, which will scroll through to voltage, then to time, when the hours is flashing, press the beam flasher button (on left hand switch gear, top push button, NOT the red high/low bean switch) to adjust the digits. When hours done, press 'D' again to do minutes in exactly the same way. When finished keep pressing 'D' until returned to original coolant temp and time screen. THink thats right!