Hello, thanks for checking this out. I've come up with a mind boggling thought experiment (at least for me it is), and any insight is welcome. Let's say you own an airplane, and you fly west with the same angular velocity as the earth's rotation. Let's also suppose we have a very special clock which determines the time based on your angular position and the direction to the sun. So, having reached the correct speed at exactly noon, your special clock now stays fixed at exactly noon, for as long as you fly at that speed. But at some point in your long flight, the date increases, even though you've been flying at noon for hours. What location are you above when the date increases? What location is the 'furthest in time' - as in the first place to change to a new date? What sense does this make? thanks.