This is a condition in which a patient wakes up too early in the morning and gets sleepy early in the evening. It is common in older people.

a circadian rhythm disorder in which sleep onset occurs in early evening and as a consequence, wakefulness occurs in early morning. This disorder is more common in the elderly.

disorder in which the major sleep episode is advanced in relation to the desired clocktime, that results in symptoms of compelling evening sleepiness, an early sleep onset, and an awakening that is earlier than desired. This is classified as a circadian rhythm disorder. The sleep phase occurs well ahead of the conventional bedtime and the tendency is to wake up too early. The major complaint may concern either the inability to stay awake in the evening, or early morning awakening insomnia, or both.

(ASPS) - Phases of the daily sleep/wake cycle are advanced with respect to clock time. This is classified as a circadian rhythm disorder. The sleep phase occurs well ahead of the conventional bedtime and the tendency is to wake up too early.

Advanced Sleep Phase Syndrome (ASPS) occurs when a person's "body clock" (i.e., circadian rhythm) is set to fall asleep very early in the afternoon. Individuals with ASPS wake up very early (or during the middle of the night) and are unable to fall back asleep.

A circadian rhythm disorder in which phases of the daily sleep/wake cycle are advanced with respect to clock time. The sleep phase occurs well ahead of conventional bedtime, creating a tendency to fall asleep or wake up too early.

Advanced sleep phase syndrome (ASPS) is a sleep disorder in which patients feel very sleepy early in the evening (e.g. 18:00-19:00) and wake up very early in the night (e.g. midnight, 1:00, etc.).