Other clocks will have one dial that moves both hands. On many wind-up alarm clocks, the alarm is set by pulling out the button that is used to set the time the alarm will go off. Atomic clocks, sometimes called radio-controlled clocks, pick up the signal of the National Institute of Standards and Technology's atomic clock from a radio transmitter in Fort Collins, Colorado. Turn the Set Knob until the alarm hand is set to the desired alarm time. On some models, there is a separate button, usually labeled "Alarm," which should be pulled out to set the alarm. DIAL LIGHT . This button may be located on the top of the clock. Slide the Alarm Switch to the OFF position; Make sure the Set Knob is pushed in. ALARM SETTING . Some clocks will use one dial for each hand.

There may also be a dial to set an alarm, which is usually a smaller hand that is a different color than the other ones. If you want your clock to be as accurate as possible, you have to go for an atomic wall clock. Activate the alarm. Common atomic clock brands include Howard Miller, Bulova, La Crosse and Seiko. Slide the Alarm Switch to the ON position. Plug the adapter for the light into AC Adapter Port [D) on the back of the clock.