There's an old Zen story about how the young initiate asked the Master: "How do you practice Zen?"
"When I'm hungry, I eat. When I'm tired, I sleep," he replied.
That's really all there is to it.
About 2014, my body got used to getting up at 0400 to go turkey hunting, and it never stopped. That means I end up going to bed early and waking up ridiculously early, but that's what my body's telling me to do. I do it. I tried to fight it at first, but I found out this was not to be. It's handy for hunting, and I've found it is handy for a lot of other things. I get most of my work done for the day before sunrise.
Eating? I'm diabetic. I found one of the best ways to deal with it was to do a strict routine of eating. I eat 3 meals a day with a day-to-day variation of only a few minutes. I eat when I'm hungry and my body pretty much picked that time.
EST? EDT? It doesn't really matter. Over the winter I've been going to bed around 7. After the time change, it moved to 8.
