Einstein's time dilation aside, that a moving clock is measured to tick more slowly than an observer's "stationary" clock, here are some examples on how flying from Narita Airport in Japan to the U.S. west coast can arrive with the hands of the clock turned back or forward in time.
How is that possible? Japan, at the time of the flights shown was 17 hours ahead of the west coast. Japan currently observes Japan Standard Time all year long. Daylight savings time has not been observed since 1951. Since the flight between Tokyo's Narita airport and San Francisco takes 8 and one-half hours, and that still leaves over seven hours of excess time that appears to take the traveler back in time. With the U.S. California observing daylight savings time in the summer, the time different drops to 16 hours.
Look at the flight from Los Angeles to Narita. It takes 11 and one-half hours. It is an hour longer due to that fact that the flying time from Los Angeles to San Francisco is an hour, but the other two additional hours are due to the jet stream aloft, which generally travels west to east, slowing the ground speed of the aircraft by the speed of the prevailing headwinds. But notice that the local times make it appears to take well over a day. Why?
Finally, why the circular route? Why not straight from point to point? Actually the route is straight. On a 3D globe you would see that the route is straight from point to point. The 2D representation of the earth distorts that straight path. More information from Flightradar24
here.
One more thing:
Here
is a time elapsed photo of a days worth of air traffic over the Atlantic from a few years ago by flightradar24.com.