Why do people generally get up at or after sunrise and go to bed past sunset instead of getting up before sunrise and going to bed at sunset?

Answer 1

Humans need sunlight for hormone production (melatonin) and vitamin production. Apart from that, the vast majority of humans for the vast majority of history needed to hunt or farm, both needing light - and daylight was/is the only available option.

Answer 2

Humans have evolved to be diurnal creatures, meaning we are naturally more active during the day and restful at night. This pattern is influenced by our internal body clock, called the circadian rhythm, which is regulated by exposure to light. Daily routines that align with the natural light-dark cycle support overall health and productivity.