I experience something that you could call 5 AM/6 AM brain. I just wake up and basically would be ready to start work.
It gets to be troublesome on some days, because the bright and early is too early
I work from home, so I have the option of taking a nap, but I prefer not to, if I can help it. I've had bad sleep problems in the past. Since starting with melatonin, the cycles have been okay. Currently I place the reason for 'time confusion' on booze.