Using the Lightphoria at any time of day directly affects your alertness. The best time to use it is in the morning. Do not use the device late in the evening. If you use it within 3 hours of going to bed, it could disrupt your sleep. If you find it difficult to get up each day without an alarm clock or if you often sleep in, you need morning light. Use the Lightphoria within the first two hours after waking up. If you find it difficult to stay awake in the late evening and wake up too early in the morning, you need evening light. Use the Lightphoria whenever you feel tired. If mornings or evenings do not seem to be the problem, but you feel generally tired during the day, then the time at which you use the Lightphoria is not as important. You can use the device in the morning or around midday. For example, when you wake up in the morning, use it for 15 to 30 minutes and then again at midday or in the evening for approximately the same amount of time. Place the device further away from you during the evening session. Do not use the device within two hours of your desired bedtime or you may not be able to fall asleep.