I have tried this. Woke up at 1AM and went to bed at 7PM for one internship.
The challenge was that there are very rarely obligatory early morning events. There are often late day events and issues.
If I wake up early, I can't stay until 9PM without being miserable. But something requiring me until 9PM is far more likely than something at even 8AM.
Why not something less extreme? I start work at 6-7 and that usually buys me a couple of really productive hours before people start popping up. It also means you can still do things at 9PM without compromising your sleep patterns too much.
1AM is extreme. I wouldn't even call that waking up early, more like just staying up all night. When I was in high school I worked 10PM to 7AM, and that was terrible. But, I was able to, at a young age learn exactly how much sleep I need and what it took for me to sleep (pitch black darkness - eye mask).
Now, I consider 5-6AM early and that's when I typically wake up - haven't used an alarm in years.
The challenge was that there are very rarely obligatory early morning events. There are often late day events and issues.
If I wake up early, I can't stay until 9PM without being miserable. But something requiring me until 9PM is far more likely than something at even 8AM.