The birth anniversary of Radha Rani is celebrated exactly 15 days after the birth anniversary of Shri Krishna, which is celebrated on the Ashtami date of Krishna Paksha of Bhadrapada month. In the Sanatan tradition, Shri Radha ji is considered to be the power of Lord Shri Krishna, without whom not only is he incomplete but the worship of his devotees is also considered incomplete. It is believed that by worshiping Radha ji with Lord Shri Krishna, one gets the blessings of a happy married life and all the troubles of life go away. According to the Panchang, Ashtami Tithi of Shukla paksha of Bhadrapada month will start from 01:35 pm on 22nd September and will remain till 12:17 pm on 23rd September. According to Udayatithi, the festival of Radhashtami will be celebrated on 23rd September.

First Radha then Krishna
Radhaji is Krishna's beloved, she resides in the chest of Shri Krishna, that is, she is the presiding deity of his life. She is Krishnavallabha because she provides joy to Shri Krishna. Radha worships Shri Krishna and Shri Krishna worships Radha. Both of them are mutually adorable and worshipable, that is, both are each other's favorite deities. According to the scriptures, after pronouncing the name 'Radha' first, the name 'Krishna' should be pronounced. If this order is reversed then the creature becomes guilty of sin.

Krishna was worshiped first
According to the scriptures, on the full moon day of Kartik, Shri Krishna worshiped Radhaji in the Rasmandal of Golok. Keeping Radha-Kavach in a Gutika of the best gems, Shri Krishna along with the Gopas wore it around his neck and right arm. After paying attention and praising her with devotion, he took the tambul chewed by Radha and ate it himself.

Shri Krishna also lives under Radha.
Once Lord Shankar asked Shri Krishna Lord! How can you attain this form? Shri Krishna replied, O Rudra! You can control me only by taking shelter of my beloved Radha, that is, if you want to please me, then go to the shelter of Radha Rani. In the scriptures, considering the worship of Shri Radhaji as mandatory, it has been said that if Shri Radha ji is not worshipped, then the devotee does not even have the right to worship Shri Krishna. Shri Krishna himself says that I follow the one who takes the name Radha. Hence, Lord Shri Krishna remains under them.

liturgy
To observe the fast of Radha Ashtami, after taking a bath and meditation in the morning, resolve to observe this fast as per the rituals. After this, first of all, worship Lord Ganesha and then worship Radha Rani by offering flowers, make-up items, fruits, offerings, etc., along with this you must worship Shri Krishna. Shri Radha Mantra 'Om Radhaayi Swaha' should be chanted. Radhaji is the form of Shri Lakshmi, hence by worshiping her one gets wealth and prosperity. Shri Krishna becomes happy quickly by chanting the name Radha. According to Narad Purana, by observing 'Radha Ashtami' fast, a person learns the secret of Brij and resides in Radha Parikars.