Shri Pushkar Bhatnagar has presented erroneous information for the effect of the phenomenon of ‘precession of equinoxes’ on correspondence between lunar months (Chaitra, Vaishakha, etc.) and seasons of the year.
This assumption resulted in a disaster for his Ramayana dating research.
In chapter II of his book ‘Dating the era of Lord Ram’ (Rupa Publications India Pvt. Ltd. 2004 and 2011), Shri Pushkar Bhatnagar states…
“This practice of adding an intercalary month for synchronisation between the lunar and the solar year was also prevalent in the times of the Rig Veda . At 1.25.8, the Rig Veda speaks of twelve and thirteen months in a year with clear mention of an intercalary month. The adjustments in the lunar and solar months were made and the calendar for the year was made by the astronomers after actually observing the movement of the sun and the moon from one zodiac to another. As a result of the adjustment due to Adhik-maas, even after thousands of years, we have Chaitra as the first month of Vasant Ritu. As against this, the English calendar counts only 365.25 days and marks the end of the year.” (emphasis mine)
[Pushkar Bhatnagar ( ). Dating The Era of Lord Ram (Kindle Locations 294-298). . Kindle Edition.]
The purpose of Adhika-masa is multifold.
(it is/was also employed to make periodic finer corrections not discussed here)
(1). To bring lunar calendar in tune with the solar calendar; Indian calendar being a Luni-solar calendar.
(2).This ensured correspondence between lunar months and seasons remained the same over a period of time (5, 10, 15, 50, 100 years).
(3). To match what was seen in the sky (e.g. position of full moon near a specific Nakshatra which in turn was used to determine the nomenclature for a given lunar month) with what was assumed/employed as the lunar month, in time calculations.
One may refer to both of my books (MW and HR)to understand beauty and intricacies of Indian Luni-solar calenda and know more about Adhika-masa, Kshaya-masa, Nakshatras, planets, comets, and much more.
However addition of Adhika-masa is not capable of preventing the shift in the seasons with that of lunar months. In fact this phenomenon (of shift of seasons with the lunar months) is a lucky gift for researchers of Ancient Indian history, in estimating/determining timing of ancient events.
Thus, without going into the specific Rig-Veda references (which, unfortunately, Shri Pushkar Bhatnagar has not presented in his book), we should understand that if there is a reference for lunar month of Chaitra occurring during the season of Vasanta (spring), then such reference would have to be due to the fact that that observation of Rig-Veda was made sometime around 24,000 BCE, when lunar month of Chaitra coincided with the season of Vasanta (spring), as is the case in our times.
What researchers of Ancient Indian history must understand is that correspondence between a timing of season and its corresponding lunar month would shift by ‘one lunar month’ approximately every ~2000 years.
Thus, during 5114 BCE, proposed timing of Ramayana by Shri Pushkar Bhatnagar,
The Lunar month of Chaitra coincided with the peak of Shishir (winter) season- i.e. at the intersection of Hemant (autumn) and Shishir (winter) season and not during the Vasanta (spring) season as claimed by Shri Bhatnagar.
This error led Shri Pushkar Bhatnagar to propose a timeline that conflicts not only with descriptions of Valmiki Ramayana but also with Shri Bhatnagar’s own assumptions of seasons for specific instances of Ramayana.