The perception that waking early is healthier than waking late, despite equal sleep duration, arises from cultural and biological factors. Societally, early risers are often associated with productivity, discipline, and moral virtue, reinforcing this belief. Biologically, aligning wake times with natural light supports circadian rhythms, enhancing sleep quality, mood, and energy levels. Early mornings typically offer quiet time for exercise, planning, and healthy routines, promoting well-being. Historically, agricultural lifestyles necessitated early rising, ingraining this link. While sleep duration is vital, timing affects sunlight exposure and social synchrony, which can reduce stress. Thus, the enduring association between early rising and health persists, though individual chronotypes matter.

I think as long as you feel good, they are both ok.

Getting up early can make someone have the control of his or her life. It's important.

It may have its scientific roots.

I think we must use Chinese traditional medicine. In China there are Yin and Yang. Our body need to adapt to the change between Yin and Yang. Daytime is the Yang and night time is the Yin.

because sleeping early  is  good for  body is  a  common sense 

have a try. It's true.really healthier. 

I don't know, maybe because when we stay up late, we will feel very weak.