If you read my diary, you'll note that some days are just
missing, with comments like [never happened] or Hey, what happened to
Tuesday? These all correspond to a flight from the USA to Australia; I leave late
in the evening on one day, and before I wake up, I have crossed
the International Date
Line (gaining a day), and also past midnight in the USA and Australia, gaining another
day. The result is that I really don't experience the intervening day; it's gone.
Amusingly, this first occurred to me in a dream in August 1967, where I was keeping my diary on paper, and would have had a real issue
with a blank page.
In the other direction, things are even more amusing: the date line compensates for the
night, so I typically arrive “before I left”.