Alertness level is predicted on computers or sliding charts (21) by relationship of sleep drives (7) and wake drives (3, 5), which are separately moved relative to destination time and time zone differential. Wake drives are moved with home time. Sleep drive is moved with bedtime (15) and sleep debt relative to tunes and a sleep debt scale (19), respectively. Resulting displays predict alertness, drowsiness, wake drives in relation to sleep drives, best bedtime, sleep debt (17) and illumination recommendations.
JET LAG FORECASTER