Hanuman Jayanti is celebrated on the full moon day (purnima) of the Hindu lunar month of Chaitra.
A special feature of Hanuman Jayanti is that according to some religious almanacs (panchangs) the birthday of Shri Hanuman Ji falls on the fourteenth day (chaturdashi) in the dark fortnight of the month of Ashvin while according to others it falls on the full moon day in the bright fortnight of Chaitra. On this day, in a Hanuman temple spiritual discourses are started at dawn. Hanuman Ji was born at sunrise. At that time the spiritual discourse is stopped and the offering of food (Prasad) is distributed to everyone.
Hanuman Ji is regarded to be the son of Hindu deity ‘VAYU DEV’ (the wind). He was taken by 'Vayu' to Lord Sun to gain Vedic, shastra's and moral knowledge. He gained his whole knowledge from Lord Sun, as he was considered as omniscient on the planet earth.