5000 years ago, in the month of Bhadrapada when the moon entered the auspicious 4th Nakshatra named Rohini on the Ashtami tithi in Krishna Paksha and all the other planets were auspiciously placed either in their own rashis or in their exaltation rashis, the atmosphere was permeated by an unearthly serenity and purity; the lakes, rivers and other water reservoirs were filled with crystal clear water and lotuses bloomed in all directions; the gentle breeze carried with it the fragrance of the various forest flowers blooming in Vraja; the sacrificial fires were burning nicely and the Brahmanas were able to perform their worship peacefully, which would otherwise be obstructed by the associates of the wicked King Kamsa, and all the people on the earthly planet were filled with a transcendental feeling of bliss. When the atmosphere was thus made auspicious and pleasant, the Supreme Personality of Godhead Sri Krishna appeared as the son of Vasudev and Devaki in the prison house of Kamsa, while simultaneously appearing as the son of Nanda and Yashoda in Gokul, thus blessing them by excepting them as his parents. It has been explained by the acharyas that Krishna never leaves Sridham Vrindavan, Vrindavanam parityajya padam ekam na gacchati, therefore it can be understood that Sri Krishna actually appeared in Gokul from the womb of Srimati Yashoda devi, while his expansion Sri Vasudev Krishna appeared in Mathura in the prison of Kamsa. Thereafter, being instructed by Krishna, Vasudev took him to Gokul, placed him next to Mother Yashoda and instead took the baby daughter of mother Yashoda, who is none other than Yogamaya, the sister of Krishna, and when he came back it appeared as if he had never even left. This was possible due to the arrangement of the internal potency of Krishna, who made the guards of the prison fall into a deep sleep and all the locks on the doors to open on their own accord. Yamuna devi also gave way to Vasudev so that he may be able to carry Krishna to Gokul. Due to having been extremely exhausted from the childbirth, mother Yashoda fell into a deep sleep and did not realise what had transpired during the night. The next day, Maharaj Nanda celebrated the birth of his son with great jubilation, giving in charity thousands of cows to qualified Brahmanas and satisfying all the Vrajavasis with various gifts. The Vrajavasis, being ecstatic, celebrated the occasion by throwing butter, yoghurt, ghee and other auspicious items on each other, thus welcoming Krishna, their very life and soul.
In Sri Vrindavan dham, the devotees celebrate the appearance day of their beloved Lord Shyamsundar with great enthusiasm. In the Krishna Balaram Temple, after taking darshan of the Lords with a new outfit both at the time of Mangal arati and Darshan arati, when the lords are dressed in a beautiful outfit and decorated with various splendid ornaments and fragrant flowers, oozing nectar from every pore of their transcendental forms which submerges the devotees in an ocean of bliss, the devotees start engaging in speaking and hearing the glories of Giridhari, the lifter of the Govardhan hill. After the glorification, all the devotees engage all their time and energy in the service of the lord in various ways, till 10’o clock at night when they all assemble for the gorgeous Abhishek ceremony of the deities of Krishna Balaram and Radha Shyamsundar. The Abhishek which is accompanied by the heartfelt singing of the Holy Names by all the devotees, is followed by an elaborate bhoga offering comprising of an unending variety of delicacies. At midnight, the lords are offered an Arati, witnessing which fills the hearts of all the onlookers with immense pleasure and a feeling of relief from the miseries of material existence. This is followed by ekadashi prashad for all the devotees, who had been fasting the whole day and engaging only in service.
The festivities, however, continue the next day, when Nandotsav is celebrated and all the devotees perform various services for the pleasure of the lord and a huge feast is offered to the Deities, which is then honoured by all the devotees with great relish to their hearts content.