Setting the Clock on the 2004 GMC Safari

• 1). Tap the "Set" button on the radio. Push and hold the "Left Seek" button within five seconds. As you're holding the button, the hour changes.
  
  
• 2). Let go of the "Left Seek" button when the hour displays correctly.
  
  
• 3). Push and hold the "Right Seek" button. This changes the minute. Release it when the minute shows the correct time.
  
  

Setting the Clock on the 2004 GMC Sierra

• 1). Push and hold the "HR" or "H" button, depending on which radio your Sierra has, for two seconds. This brings you to the clock setting mode.
  
  
• 2). Tap the "HR" or "H" button to adjust the hour.
  
  
• 3). Push and hold the "MN" or "M" button, depending on which radio your Sierra has, for two seconds.
  
  
• 4). Tap the "MN" or "M" button to adjust the minute display.
  
  

Setting the Clock in All Other 2004 GMC Vehicles

• 1). Push and hold the "HR" or "H" button, depending on which radio your GMC has. As you hold the button, the hour changes.
  
  
• 2). Release the "HR" or "H" button when the hour shows the correct time.
  
  
• 3). Push and hold "MN" or "M" to set the minute.