Even though the day seems short, actually it is very long.
When I used to travel (Pre-Covid 19) on a long flight of 14-15 hours, I was able to work, to sleep, to watch a movie, to read, to write, to eat, to catch up on emails and I still had several hours of flight time left! Why? No interruptions!
If you want to expand your day stop the clock by avoiding unnecessary interruptions.