In Karnataka Hanuman Jayanthi is celebrated on Margashirshamaasa Shukla Paksha Trayodashi. According to Maharshi Valmiki, the author of Srimad Ramayana Hanuman was born on Chaitramaasa Poornima.
Then what is the relevance of this day???
Jnanis say that it was on this day Hanuman met Shri Rama and Lakshmana on the Rishyamukha Parvata (Mountain) in Kishkindha. At that time Hanuman was the Sachiva (Minister) of Vaanara King Sugriva. King got the information that two youngsters, armed with bows and arrows were proceeding towards the mountain. Curious and anxious with the thought that his brother Vaali might has sent them to spy upon him, Sugriva requested Hanuman to go and enquire. Hanuman disguised himself as a Sadhu and approached them.
Maharishi Valmiki has captured the excellent conversation that takes place and noted it in Srimad Ramayana. The conversation is as follows:
Hanuman said “You both look like Rajarshis and Taapasvis but you are armed with bow and arrows. Animals in this jungle are frightened in your presence. Your eyes resembles petals of lotus and you have broad shoulder with vast chest. You seem to be unbeatable in a fight but yet look like saviour of many lives. You seem to be like divinity in guise of a human. These contradictory observations bewilder me a lot. I am Hanuman, Sachiva (Minister) to Sugriva. Sugriva is the Vaanara King banished by Vaali, the King of Kishkindha. He is also the elder brother of Sugriva. My King Sugriva is a righteous person and wishes to seek your friendship. I want to hear a reply from you.”
Shri Rama after listening to Hanuman, said to Lakshmana, “Lakshmana, Did you observe how articulate Hanuma spoke! There is nothing impossible to a King who has a Sachiva (Minister) like him. Even a foe who has come with an intention to kill will fails to act after listening to Hanuma. A King is so lucky to have a minister like him. By analysing his words he seem to be well versed in Rigveda, Yajurveda, Samaveda, Vyakarana (Grammar) and Upanishads. One can never talk like this without the gaining knowledge from those granthas (Literature). His eyebrows and forehead didn’t move unnecessarily. His voice was neither too loud nor like whisper. He started, continued and completed his words in a single tone. He particularly knows how to spell each and every syllable. Sugriva is very lucky to have Hanuma under him. Lakshmana, convey him our purpose and the circumstances of our presence in this forest.”
Lakshmana then explained Hanuman their whereabouts and about missing Sitadevi.
After knowing that the two princes he was talking with were none other than his beloved Shri Rama and his brother Lakshmana from Ayodhya, Hanuman was overwhelmed with joy! He immediately revealed his identity and prostrated before Shri Rama’s feet. This day was so important in the life of Hanuman that an immortal bond generated between the Danni (Master) and his Daasa (Servant). This day engulfed so much in his life that it became his new birth. Hence Margashirsha Shukla Triyodashi is the Janma thithi of Hanuman.
We have heard that after Vaali was killed and the Kingdom of Kishkindha was restored to Sugriva. Varsha Ritu (Rainy Season) started and only after the rain receded did the Sita Anveshana (Search for Sitadevi) take place. Our Hanuman was the most important member of that anveshana.