There was a program going on on Zee News just now that was talking about the dates from Ramayana. Valmiki records the birth of Rama as Chaitra Shuddha Navami (9th), on Punarvasu Nakshatra and five plants were exalted then; Sun in Mesha upto 10 deg., Mars in Capricorn at 28 deg., Jupiter in Cancer at 5 deg., Venus in Pisces at 27 deg. and Saturn in Libra at 20 deg. (Bala Kanda.18/Shloka 8,9). The date mentioned in this website for the date of birth of Rama matches with the program – i.e. 10th January 5114 BC. The planetary positions are mentioned and can be looked at here. http://www.historicalrama.com/rama-navami.gif. I put these dates in JHora software, which also claims to use the state of the art ephemeris and an accuracy range of –5400 to 5400 years. Between the two softwares, the main difference is the position of Saturn. The JHora software shows Saturn in Scorpio by couple of degrees. Moon is also shown in Pushya nakshatra in the labha, while Rama was said to be born in Punarvasu nakshatra with Moon in Lagna. Thus, the dates don’t match as such.
The program also mentioned the date of Dussehra to be 4th December 5076 BC, but the date has a major issue that it falls in Phalgun month. The guests on the program mentioned that the research on this this still in progress. Another site on the web http://www.hindunet.org/hindu_history/ancient/ramayan/rama_vartak.html also mentions that Ravana was killed in the month of Phalgun. Have all of us Hindus been celebrating Dussehra & Diwali on wrong dates?