Was up late last night, woke today 11:30AM.
Man, the difference between waking at 4:30 and 11:30 is staggering. If I had to guess, I think I'd guess somewhere between 300% and 500% higher productivity for being up at 4:30AM.
If you do "standard morning stuff" after waking for 30-60 minutes, shower, groom yourself, and eat, you can sit down to work sometime between 5AM to 7AM on the early schedule.
You're starting between noon and 2PM on the late schedule.
Why's it matter? A lot of things. Psychologically, the "ahh, I'm up early" helps. Then, it seems like we naturally start to slow down when it starts getting darker at nights.
If you work in cafes or have to run errands, places are much less crowded during the daytime hours than the evening hours. So you can knock all that out, and then take it easy from 5PM+. If you're only starting work at 2PM since you're on the late schedule, you're going to be working until later at night with more people around.
It also changes the general texture of your life. If you're up late, you're more likely to go out and do entertainment type stuff in the evenings instead of turning in early, and things like that. Of course, there's advantages to that, but not when you're in a busy work period.
Then of course, for the 9-5er, the difference is even bigger between a 4:30 schedule and, say, a 7:30 wakeup time. It's almost impossible to get peak creativity/enterprising out of yourself after an eight hour workday, but it's very easy to put in 3 good hours in the morning before work.
Waking up very early also makes it easy to nap in the afternoon and split your day in two, which helps for productivity especially if you've got evening social engagements. That's much harder to do on the late schedule.
I'm going to double down on my morning schedule. It's far superior to the later one for getting things done.