The archeological excavations of the cities of Harappa and Mohenjadaro has shown evidences of the Mahabharatha. There has been numerous attempts to date the occurrence of the Mahabharatha. I am currently reading the book "ಶ್ರೀ ಮಹಾಭಾರತ ಪಾತ್ರ ಪ್ರಪಂಚ" by Prof. K.S.Narayanacharya which describes the exact date of the various incidents in the story of Mahabharatha based on the astronomical evidences present in the epic itself. I am listing here the dates of the various incidents of the Mahabharatha as provided in the book.
- August 31st, 3114 B.C, Tuesday - Birth of Yudhisthira
- July 26th, 3112 B.C - Friday - 11:40PM - Birth of Sri Krishna.
- Arjuna born in Shukla Chaturthi - Uttara Phalgni Nakshatra on a friday. He is 47 days elder to Krishna.
- Pandavas returned back to Hastinavati after Pandus death in July 3099 BC. Yudhisthira was 14 years 9 months 11 days old.
- Draupadi's swayamvara - April 3091 B.C
- Building of Indraprasta - November 3091BC
- Rajasuya Yaga was performed by Yushishira -Nov 3083BC to Oct 3082BC
- Abhimanyu was born in February 3083 BC
- The game of "Dyutha" and Pandava vanavaasa started in Nov 3081 BC for a total of 13 lunar years + 5 lunar months +12 days.
- Agyaata vaasa began in Margashira maasa 3069BC. Margashira Krishna Navami, 3068BC, Arjuna was spotted by Kauravas in the Virata war.
- The war of MAHABHARATHA -Started on Friday, Margashira Shukla Ekadhashi in Krithikka Nakshatra. November 22nd 3067BC. This is the same day when the discourse of Bhagavad Gita took place in the battle field of Kurukshetra.
- The war went on for 18 days.
- Bhishma died on Shukla Ashtami - 58 days from the start of the war.
- Post war, Yudhishira ruled for 36 years.
- End of Krishnaavatara - Friday, 13th April, 3031BC
- Start of Kali Yuga - 13th October, 3115BC
Similarly there are evidences for the dates of Ramyana. For eg: the birth date of Rama is found to be January 14th ,5114BC. More details here :http://www.hitxp.com/articles/history/birth-date-rama-born/