According to Valmiki Ramayana, Sri Rama was born on the 9th day or the ninth tithi, also known as Navami, of the waxing moon fortnight, otherwise known as 'Shukla Paksh', in the month of Chaitra, sometime in antiquity.
The other pointers to the planetary positions at the time of Sri Rama's birth in Valmiki Ramayana are that Sri Ram's birth ascendant was Cancer, the day was advancing which indicates that the birth happened between 12 noon and 1 pm, that five of the seven planets were exalted. It also says that Moon was placed with Jupiter. In saying that the presiding deity is Aditi, Rishi Valmiki indicates that Sri Rama was born in the Punarvasu Nakshatra.
This also indicates that Moon had to be located between 0 degrees to 3.20 degrees of Cancer, since it is only between 0-3'20 degrees of Cancer, when Moon is associated with Cancer in the Punarvasu Nakshatra.
In one shot Rishi Valmiki describes all the planetary positions we need to calculate Sri Rama's birth chart. Here is the verse from Valmiki Ramayana:
ततो यज्ञे समाप्ते तु ऋतूनाम् षट् समत्ययुः |
ततः च द्वादशे मासे चैत्रे नावमिके तिथौ || १-१८-८
नक्क्षत्रे अदिति दैवत्ये स्व उच्छ संस्थेषु पंचसु |
ग्रहेषु कर्कटे लग्ने वाक्पता इंदुना सह || १-१८-९
प्रोद्यमाने जगन्नाथम् सर्व लोक नमस्कृतम् |
कौसल्या अजनयत् रामम् सर्व लक्षण संयुतम् || १-१८-१०*
Since Moon and Jupiter are together in Cancer in the first house or ascendant, it caused one of the best forms of Gaj Kesari Yoga. Jupiter is exalted, and Moon is in its own sign in Cancer. What could be better than that! And five exalted planets made him an divine, an emperor who's fame has refused to fade away. But we are looking at Lord Rama's planetary positions here from a point of view of astronomy, and not astrology! Though both are intricately tied up with one another!!
This planetary data was fed into the Planetarium Software, a software which is now declassified, (it was earlier not available to public) and was used by NASA to calculate the exact position of planets for any given date - past, present or future, within a limit (unknown). The closest date from today into the past, for which the planetary data of Lord Rama's birth fits in, is 10th January, 5114 BC. Since then this combination has never occurred in the skies which implies Sri Ram was born no later than 5114 BC.
A note on the Shift of the Precession of the Equinox: The positions of the Equinoxes move westward along the ecliptic compared to the fixed stars on the celestial sphere. This annual motion is about 1 degree every 71.6 years. A complete Precession cycle covers a period of 25,765 (71.6 * 360) years, during which time the equinox regresses over 360°. This journey over 25,765 years covers the 12 zodiacs of the sky so that the sun rises on the vernal equinox in the same zodiac for about 2,150 years.
Today, the Sun rises in the background of Pisces on the vernal equinox. We are almost at the end of this cycle, the Sun will rise in the background of Aquarius from 2150 AD onward. 2150 years back (calculated from 2150 AD) that is from 1 AD to 2150 BC, the Sun rose with Aries in the background of vernal equinox, another 2150 years before that , that is, 4300-2151 BC,in Taurus and from 6450 - 4300 BC in Gemini! This almost 4 sign shift in the precession of the equinox accounts for the roughly 4- month shift from January to April in Sri Ram's birth day month of Chaitra.
But one cannot jump to any conclusions with the results of this calculation. To prove exactly when Sri Rama walked the earth in a human avatar all other details mentioned by Valmiki must be analysed.
One such detail is the mention of the four-tusked elephant that Sri Hanuman sees at Ravana's palace at Lanka. The four-tusked elephant lived from 12 million to 1.6 million ago when it became extinct.
|Research and studies are going on around the world on|
the extinct four-tusked elephant
Given this time frame, measuring the antiquity of the Ramayana in terms of the 'yugas' that the Rishis have mentioned is far more scientific than the few thousand years we are allowed to think by mainline historians.And to pass off facts, only because they are beyond our comprehension, as myths is the biggest disservice that we do to our own history.
* Translation of the verses:
R^ituuNaam SaT sam atyayuH = seasons, six, well, passed by;
tataH = then; dvaadashe maase = in twelfth, month;
chaitre naavamike tithau = chaitra month , ninth, day;
nakshatre aditi daivatye = star of the day [Punarvasu,] whose presiding deity is aditi;
panchasu graheSu swa uccha samstheshu = of five, planets, in their own, highest, positions - in their own ucCha sthAna-s in their own exalted positions - meSha, makara, karkaTa, mIna, tula - rAshI-s;
chandra yukta guru karkaTa lagne proudyamane;
karkaTe lagne = in Cancer [of Zodiac];
vaak patiH= when Speech's, Lord [Jupiter];
indunaa saha = Moon, along with;
pra udyamane = advancing daytime