Sure, you can change timezone, but you usually feel like shit in the process. The idea seem to be that it takes about a day per hour to adjust.

Now the idea (somewhat supported by the article) is that night owls have a natural cycle longer than 24h. It means they are in a constant state of jet lag. The (unrealistic) solution to get in sync with the rest of the population would be to always go west.

Early birds are in the opposite situation. They have a natural cycle shorter than 24h. It is just that for some reason, waking up and going to bed early is not seen as a problem in our society, while the other way is.