This casio clock has a light emitting diode led is used to illuminate the watch face and the daily alarm reminds you of events that recur every day by emitting an audible signal at the set time each time you stop the alarm it sounds again after a few minutes while times can be displayed in either a 12 hour or 24 hour format led a light emitting diode led is used to illuminate the watch face daily alarm without an hourly chime an accoustic signal goes off daily at a set time snooze featur