What kind of condition is a delayed sleep phase?

Circadian disorder: Delayed sleep phase syndrome (dsps) is partly a genetic condition that results in the delayed timing of sleep with respect to the signal generated by the endogenous biological clock. One's habitual schedule of exposure to light and dark can contribute to and maintain dsps. Moving one's wake-up time earlier by increments each day, evening melatonin, or morning bright light can ameliorate dsps.