I'd rather be cautious with such assessments like "absolutely a natural night owl" – at least until we're able to tell that from the genome directly, haha.

I'm a night owl myself, but around 10 years ago I've accidentally switched to the 10pm-5am sleep pattern and those were happiest and most productive months of my life. I was waking up without alarm and was jumping out of bed, quite literally. I dream to return to that pattern again and have been trying to do so since then (no luck so far).