Locate the Source button. Press and hold this button until the car stereo shuts off.
Press and hold the Source button a second time until the unit turns back on and the clock appears. If your Pioneer car stereo does not have a Source button, press and hold the Function or Audio button instead.
Use the left or right arrow keys to choose the segment of time you want to change.
Change the time to your desired setting by using the up or down arrows.
Press the Source button at the end of the process to complete the change and save the new setting.