The New York to Italy example in the article is a bit confusing to me. Seems that there's about 6 hours difference between Milan and New York, and the flight itself is 8~9 hours. Leaving New York at 6PM, arrives Milan at 3AM EST, 9AM Milan time. "Instead of shifting you earlier to Italian time, it makes you feel it’s even later — that the night is over and it’s already morning." Does the body choose to this because shifting to "already morning" is smaller difference(6 hours) than "still not night time" (18 hours)?