Think of this way, it's healthier to rise with the sun. That's how we've evolved for billions of years.
It's unhealthy to rise an hour before the sun. It's unnatural.
Call it 3 in morning, call it 10 in the morning.
??? It's not what we call it. It's when the sun actually rises. Like it or not we've arranged our society to start at 8 am (or 9 am in some places), so no we can't get up whenever we want.
And you do understand our circadian rythyms are connected to the sun right? The sun dictates our rhythms, not the other way around.