Having identified the place where Sita had been held captive, Hanuman returns to his capital Kishkinda and informs Rama and Sugreeva, of how Ravana was holding Sita in captivity. Sugreeva garners his Vanara army to march southwards from his capital Kishkinda, towards Lanka.
Before embarking on their journey for the battle, they look for the right omens, for the army to start their march. The discussions around these omens are useful for us today, to clearly date the start of the army march.
“Today the sun has already risen to the middle of the sky and this is the famous Vijay Mahurath. In my opinion we must start our journey towards Lanka in this Vijay Mahurath, to win the battle against Ravana.”
– Ramayana 6.4.3
“Today is Uttara – Phalguni Nakshatra and tomorrow the moon would meet the Hasta Nakshatra. O Sugreeva! We must start our journey immediately along with the army of Vanara.”
– Ramayana 6.4.6
Start of the Army March to Lanka – 19th September 5076 BCE
The start date of the Vanara Army march as calculated from skychart is 19th September, 5076 BCE.