Morning Phototherapy involves exposure to bright light upon awakening. It helps to increase morning alertness and advances the sleep phase in the evening. An inexpensive way to get exposure to bright light (depending on weather conditions, the location and season of the year) is to open the window shades or take a walk in the bright morning sun. Alternatively a specially designed bright light box may be prescribed. These boxes provide between 2,500 and 10,000 lux . Depending on the brightness level, they are used for periods of 30 min to 2 hours. Precise timing of use is critical and is related to the core body temperature minimum. The light is administered about 30 minutes earlier every other day to help gradually advance evening sleep onset. This treatment can be effective in 2 to 3 weeks when combined with evening light avoidance, but often requires ongoing treatment to maintain gains.

Ingestion of oral melatonin later in the day has the effect of advancing the onset of sleep. Proper timing is again critical and is dependent on the dim light melatonin onset which occurs about 14 hours following the habitual wake time. A reasonable estimate for the appropriate time to take melatonin for the purpose of advancing sleep onset is about 8 hours after the natural wake up time. A lower dose is recommended in order to get the clock resetting effect without creating strong drowsiness as may occur with higher doses.

Chronotherapy can be used if there is a flexible enough daytime schedule. Sleep onset is delayed[moved up?] 2 - 3 hours on successive days until the desired bed time is reached.[if desired bed time is -7h, why go +17h?] Obviously, this will be difficult for anyone with a regular work or school schedule. It may be possible to do over a vacation. Once a regular bedtime is established it must be rigorously maintained. Relapse is possible and the process may need to be repeated.