What I want to know is why can't every day be like that? The day itself. How many days have you thought, "I just need another two hours because I have all this work to do and I need to get it done today." Conversely, how often have you looked toward an event in the future and said "I wish today were already over, because I want it to be tomorrow!"
I really want the option of having one day end at, say, 6:00 PM, going to sleep for eight hours, and having it be the next morning when I wake up again. And on other days, I want to be able to work until 2:00 AM, get a full eight hours' sleep, and wake up at 6:00 AM for work the next morning.
That should be possible. It should.