A lunar calendar is based on monthly cycles of the moon’s phases. In contrast with a solar calendar which is based only on the solar year. An example of the most commonly used calendar is the Gregorian calendar. This is a solar calendar that evolved from the lunar calendar system and was developed to correct the Julian calendar. The Julian calendar was proposed by Julius Caesar and was designed with the help of Greek mathematicians and Greek astronomers.
Our moon has many influences throughout history. There are lunar influences on climate, which probably led to the lunar calendar for farming. Another influence from our moon involves the redistribution of heat on earth by the movement of tides within the water masses of oceans (Camuffo & Uniti, 2001).
The release of neurohormones may be triggered by the electromagnetic radiation and/or the gravitational pull of the moon according to Zemecki (2006) who reported that human and animal physiology are subject to seasonal, lunar, and circadian rhythms.
BBC News Online science editor Dr David Whitehouse in France, reported his visit to the oldest lunar calendar seen on the walls of the famous, prehistoric caves at Lascaux in France (2000). However, this finding remains controversial which means the oldest at this time is still the one found at Warren Field in Scotland and has been dated approximately 10 thousands years ago during the Mesolithic period.
Hope this is the start for you to learn something new!
Camuffo, D., & Uniti, C. S. (2001). Lunar Influences on Climate. Retrieved from https://link.springer.com/chapter/10.1007/978-94-010-0800-6_10
Whitehouse, D. (October, 2000). Oldest lunar calendar identified. Retrieved from http://news.bbc.co.uk/2/hi/science/nature/975360.stm
Zimecki, M. (2006). The lunar cycle: effects on human and animal behavior and physiology. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/16407788