A 20-minute assessment of
sleep latency, administered 4 times a day at 2-hour intervals, beginning 2 hours after
nocturnal polysomnography, measured time to sleep onset after a patient was instructed to remain awake while seated in a dark room without
stimulus.
My personal record (longest time to onset) without Provigil as recorded at the Princeton Hospital's sleep clinic was five minutes; with medication, I can stay awake for the duration.