We boarded Air New Zealand Flight 9 in LAX about 21:30, and left the ground soon after heading west, out over the Pacific. Something like 12 hours later, we arrived in Auckland, New Zealand around 04:00 on 1 September, 2001. That wonderful bit of magic, an imaginary line mostly following the 180 degree longitude line except for some zigs and zags to avoid landmasses of various sizes and shape is responsible. It's magical, and avoids landmasses, for the same reason; here on the globe, Yesterday becomes Tomorrow and Today never exists.
We probably slept through the exact moment the magic happened.
That line is on the 180 degree of longitude because the 0 degree runs through Greenwich, Great Britian. At some when in time a group of people agreed that this would be the starting point for determining longitude. While I'm not sure that the point of a bayonet and the muzzle of a gun played a direct role in this agreement, I am sure they played a role. Something about the British Royal Navy, and things. It's a pleasant co-incidence that 180 degrees opposite Greenwich is mostly water, being the Pacific Ocean and all. But the International Date Line does its zigging and zagging to avoid what land masses do fall on this line, or come close to it. I guess we wouldn't want anybody waking up Yesterday and strolling to work on foot to Tomorrow.