Hanuman Jayanti or the birthday of Hanuman is observed on the Chaitra Purnima (full moon day of the Chaitra month falling in April - May). There are different versions and dates of Hanuman Jayanti followed in different parts of India. However, celebrating it on The Chaitra Purnima is the most famous one in most North Indian states of India.
Different versions of Hanuman Jayanti
The devotees in Andhra Pradesh celebrate Hanuman Jayanti for 41 days starting from the Chaitra Purnima day. The celebrations last till the tenth day of Krishna Paksha (waning phase of moon) in the Vaishaka month (May – June).
In the state of Tamil Nadu, people celebrate Hanuman Jayanti on the Marghashirsha Amavasya (No moon day during the December – January)
Hanuman Jayanti is known as Hanumat Vratam in Karnataka. It is observed on the Shukla Paksha Trayodashi (thirteenth day of the waxing phase of moon) in the month of Marghashirsha (December – January)
How to celebrate Hanuman Jayanti
Hanuman is a very popular god for the Hindus. He is known for his valour, courage, devotion to Lord Rama and steadfastness. Hanuman is also a merciful god who is benevolent to his devotees. On the day of Hanuman Jayanti, people observe a day long fast. Since Hanuman was born during sunrise, the Hanuman Jayanti celebrations start very early in the morning and conclude shortly after sunrise. Elaborate pujas, decorations and programs are organized in Hanuman temples. Most popularly, people sing Hanuman Chalisa and the songs of Lord Rama on this day to please Lord Hanuman.