Hanuman Jayanti is a Hindu festival that celebrates the birth of Lord Hanuman, a key character in the Ramayana. It's a day to honor Hanuman's strength, courage, and devotion, and to seek his blessings. 

Why it's celebrated

To celebrate Hanuman's divine qualities: Hanuman is a symbol of strength, courage, and selfless service. 

To emulate Hanuman's virtues: Devotees aspire to emulate Hanuman's virtues in their own lives. 

To seek Hanuman's blessings: Devotees seek Hanuman's blessings for happiness, prosperity, and spiritual fulfillment. 

How it's celebrated

Devotees pray, fast, and recite the Hanuman Chalisa. 

In Karnataka, devotees tie a sacred thread with 13 knots while chanting the mantra 'Om Namo Vayunandanaya Om'. 

When it's celebrated 

Hanuman Jayanti is celebrated on the full moon day (Purnima) of the Hindu lunar month of Chaitra. This day usually falls in April or March as per the Gregorian calendar.