Culture of our land is culture of introspection and rich observation. We have many realized souls since time immemorial who equated human body as reflection of the outer universe. Whatever exists in our world outside, is present in our body. With the central role given to the notion of equivalence between the microcosm and the macrocosm, it is natural to assume that the Vedic people had found many connections between biological and astronomical processes. The most fundamental biological rhythms are matched to the periods of the sun or the moon.
For example, a daily cycle of activity observed in many living organisms, including humans, is called circadian rhythm.
This circadian rhythm is not the 24-hour one related to the motion of the sun but rather the 24 hour 50 (aka 24.50 cycle) minute one according to the period of the moon, since each moonrise is 50 minutes later than the preceding one. We share this approximately 24-hour-50-minute clock with monkeys and other non-humans.
This 24.50 cycle was discovered by modern science mere 40 years back but scriptures of Bharat described it since eternity. As per Ayurveda, it is subtle body or Mind, that governs our activities. New seeds of actions are sown in mind which becomes Action in real world based on will of the soul. So it is important to keep mind healthy. And Mind is called Moon in scriptures. Like Moon, Mind too follows 24.50 cycle (circadian rhythm). So for healthy mind, it is advisable to sync Mind’s activities with outer Moon’s 24.50 cycle.
How can we sync Mind’s movement or subtle rhythm with the Moon’s (and all rest of the planets, including the Sun)?
By following daily moon rise (Astronomy based calendar and not the Gregorian calendar) and sync our activities based on moon’s cycle.
What does it mean to follow Astronomy based calendar?
Tune your daily activities based on Tithi, Var, Nakshtra, Moon’s movements, planet movements. Follow life routine based on panchang.
I often get arguments when I talk about such wonderful and vast knowledge hints in our scriptures. Arguments like:
“Oh you are so communal” 
😀
“Oh, you mean, to live as per superstitions?” 😀
What to answer such lame and irrational arguments?
May Maa bless them 
🙂 Living life as per Prakriti’s orders is not superstition or communal but wise and humble responses to changes governed by mother nature and to live life with minimum obstacles in our spiritual goal i.e. self-realization. Real science if you keep your ego aside 🙂 Good year ahead!
PS:Note is written based on reading of Shri Subhash Kak’s papers
