1. The cowherd men of Vrndavana observing Siva-ratri

    Once upon a time, the cowherd men of Vrndavana, headed by Nanda Maharaja, desired to go to Ambikavana to observe the Siva-ratri ceremony. The rasa-lila was performed during the autumn, and after that the next big ceremony is Holi, or the Dola-yatra ceremony. Between the Dola-yatra ceremony and the rasa-lila ceremony there is an important ceremony called Siva-ratri, which is especially observed by the Saivites, or devotees of Lord Siva. Sometimes the Vaisnavas also observe this ceremony because they accept Lord Siva as the foremost Vaisnava. But the function of Siva-ratri is not observed very regularly by the bhaktas, or devotees of Krsna. Under the circumstances, Srimad-Bhagavatam states that Nanda Maharaja and the other cowherd men “once upon a time desired.” This means that they were not regularly observing the Siva-ratri function but that once upon a time they wanted to go to Ambikavana out of curiosity.

    From Srila Prabhupada’s Krsna Book, ch. 34: Vidyadhara Liberated and the Demon Sankhacuda Killed