[Nifty3929]

Circadian rhythms are different between people, and throughout one's life. They also typically vary by demographic.

Adolescents and young adults typically have a circadian rhythm shifted a couple of hours later than younger kids and adults. Even with the best of intentions about sleeping earlier, they're likely to be sleep-deprived by waking up earlier.

[Fire-Dragon-DoL]

I also assume it varies with the season. For example it's half way through june, my body wants to naturally go to bed later and wake up earlier (11pm, 6am wake up time). I have to force myself to go at 9pm (have children), so that I get my 8 hours if sleep.

During winter when it's always dark I have no trouble going to bed at 8pm.

I'm a former night owl, used to go to bed between 4 and 6 am and wake up at 2pm every day of the week, which worked great to work for north america as a remote developer from europe