Jet Lag or a Time Machine?

I am sure that many of us who frequently travel across countries must have experienced jet lag. So, what exactly is jet lag? Jet lag is the feeling which our bodies go through due to the differential time zones followed in different countries. It is our body cycle which does not seem to understand the difference in time as a result of crossing several time zones and the different local times.

I am sure that many of you know the how and why of jet lag. But do you know that actually it is kinda a time machine ride to travel across time zones. You can actually gain time by travelling westward and conversely loose time by travelling eastward. Any traveler circling the globe in a westward direction lengthens the day by 1 hour for every 15° of longitude traveled because the traveler is following the apparent motion of the sun.

While moving westward, if the traveller has travelled completely around the world then he/she is one full day ahead of the people who have remained at the starting place of the trip. Similarly while moving eastward, if the traveller has travelled completely around the world then he/she is one full day behind the people who have remained at the starting place of the trip.

For eg. while travelling westward, if a traveller starts on 27-09-08 at from Japan, he is constantly losing time and when he completes the entire world, he is a day behind i.e. he would think it is 29-09-08 but for a person who is in Japan itself the date would be 28-09-08. The exact opposite would be for a person travelling eastward, say from America, if he were to start on 27-09-08 he is constantly gaining time and by the time he reaches America again he would still think it is 27-09-08 but for a person stationary in America the date would be 28-09-08. How would you put this phenomenon as? For me it is time travel, what about you?