You should be asleep before midnight A 2021 study on over 100k...

A 2021 study on over 100k people found that sleep onset between 10-11 PM was linked to the lowest incidence of cardiovascular disease
Sleep onset after midnight was linked to higher risk compared to 10-11 PM, highlighting the importance of circadian rhythm alignment
They did find that sleep onset before 10 PM was linked to greater risk than 11-12 PM, but that might be because of underlying comorbidities or frailty
academic.oup.com/ehjdh/article/…
