Alarm Clock for a more natural wakeup: sunrise alarm improves your ability to function in the morning. The Philips Sunrise Simulation Alarm Clock HF3500 wake-up Light gradually increases in brightness over a 30-minute period before your wakeup time, growing more intense until your room is filled with bright yellow light. This process of changing and increasing light stimulates your body to wake up naturally and comfortably. By the time light has filled the room, a gentle beep completes the wakeup experience, leaving you ready for the day ahead. Scientifically proven to be a more effective way of waking up, the Wake-up Light also leaves you more energized and in a better mood upon awakening.