A device that monitors a users sleep cycles and operates to sound an alarm to awaken the user at an optimal point within a sleep cycle. Once an alarm time is set and the alarm is activated, the device begins to monitor a wearers sleep cycles by identifying the points in time at which the wearer moves his or her body limbs. As the alarm time is approached, the device can trigger the alarm earlier if the wearer is at an optimal point in the sleep cycle or, even retard the triggering of the alarm if the optimal point in the sleep cycle is expected to occur shortly. The device can be used to assist children in waking up to prevent bed wetting, or in a patient for obtaining light therapy.