Hanuman Jayanti is celebrated on full moon day during Chaitra month. Hanuman, who is also known as Vanara God, was born on this day and Hanuman Jayanti is celebrated to commemorate the birth of Hanuman.
Devotees observe Hanuman Jayanti during different time of the year according to their regional beliefs and the type of calendar being followed. Hanuman Jayanti during Chaitra Purnima is the most popular one in North Indian states.
In Andhra Pradesh and Telangana, Hanuman Jayanthi is celebrated for 41-days which starts on Chaitra Purnima and ends on the tenth day during Krishna Paksha in Vaishakha month. In Andhra Pradesh devotees begin 41-days Deeksha on Chaitra Purnima and conclude it on Hanuman Jayanthi day.
In Tamil Nadu, Hanuman Jayanti is known as Hanumath Jayanthi and observed during Margashirsha Amavasya. In Gregorian calendar Tamil Hanuman Jayanti falls in January or December.
In Karnataka, Hanuman Jayanti is observed on Shukla Paksha Trayodashi during Margashirsha month. The day is popularly known as Hanuman Vratam.
It is believed that Hanuman was born at Sunrise. On Hanuman Jayanti day temples start spiritual discourses at dawn before Sunrise and stop it after Sunrise.
Hanuman, an ardent devotee of Lord Rama and Sita himself, is also known as Anjaneya.