Hanuman Jayanti is an important Hindu festival that celebrates the birth anniversary of Lord Hanuman, who is known as the monkey god. The festival is observed on the full moon day (Purnima) of the Hindu lunar month of Chaitra, which falls in either March or April according to the Gregorian calendar.

The origins of Hanuman Jayanti can be traced back to ancient times, and it is believed that the festival has been celebrated for over 2,000 years. The exact date of the first Hanuman Jayanti celebration is not known, but it is believed to have started during the reign of King Harshavardhana, who ruled northern India from 606 to 647 CE.

According to Hindu mythology, Lord Hanuman was born to Anjana and Kesari as a result of a boon granted by Lord Shiva. He is revered as a symbol of strength, devotion, and loyalty, and is one of the most popular deities in the Hindu pantheon.

Hanuman Jayanti is celebrated with great devotion and enthusiasm across India and in other parts of the world where there is a significant Hindu population. Devotees visit temples dedicated to Lord Hanuman, offer prayers, perform aarti, and sing bhajans (devotional songs) in his honor. They also fast and perform puja (worship) to seek his blessings and protection.

In some parts of India, a procession is taken out on the day of Hanuman Jayanti, with devotees carrying a statue or image of Lord Hanuman on a chariot or palanquin. The festival is also marked by the reading of the Ramayana, the epic tale of Lord Rama and Lord Hanuman, and the distribution of prasad (food offered to the deity).

Overall, Hanuman Jayanti is an important festival that celebrates the birth of one of the most beloved and revered deities in the Hindu pantheon, and it continues to be celebrated with great devotion and enthusiasm by millions of people around the world.