Flying East

Flying east is usually more difficult than west through time zones. I'm not sure exactly why but it is harder on one's metabolism to adjust to for some reason. For this reason if you were going to go around the world visiting places likely you would want to go from east to west if you went around the world because as you visited time zones your metabolism likely could adjust much much easier than going eastward through time zones.

For example, flying to Hawaii time zone wise was fairly easy. It is about the same difference as the east coast to California time wise different (3 hours). So, when you reach Hawaii you are 3 hours earlier than California and 6 hours earlier than New York City, for example. But, when you come back to the mainland you will notice it is harder for your metabolism to adjust in either California (Oregon or Washington)  3hours ahead of Hawaii or New York and the rest of the east coast (6 hours ahead of Hawaii.

For example, if it is midnight in Hawaii it is already 6 am on the east coast. So, don't be surprised at the difficulty you are going to have adjusting back to your original time zone after being in Hawaii.