up to 6 h		6 h<time difference<10 h		more than 9 h1
		Melatonin	Light	Melatonin	Light	Melatonin	Light
westbound		delay body clock		delay body clock		delay body clock
	day before departure	upon waking in the morning (regardless of how early)		upon waking in the morning (regardless of how early)		upon waking in the morning (regardless of how early)
	day of departure	upon waking in the morning (regardless of how early)		upon waking in the morning (regardless of how early)		upon waking in the morning (regardless of how early)
	after departure	upon waking in the morning (regardless of how early)	exposure to bright light for at least ½ h late in the day	upon waking in the morning (regardless of how early)	get midday light but avoid it later in the day, following days gradually later	when it's morning at the point of departure, each subsequent day 1-2 h later	get midday light but avoid it later in the day, following days gradually later
eastbound		advance body clock		advance body clock		delay body clock
	day before departure	afternoon		afternoon		upon waking in the morning (regardless of how early)
	day of departure	afternoon		afternoon		upon waking in the morning (regardless of how early)
	after departure	afternoon	exposure to bright light for at least ½ h in the morning	afternoon	get midday light but avoid in the morning, following days gradually earlier	when it's morning at the point of departure, each subsequent day 1-2 h later	get midday light but avoid it later in the day, following days gradually later

Annotation

1. It is easier to delay the body clock by 14 hours than to advance it by 10 or more.