In addition, Simhachalam celebrates two annual festivals: Dhanurmasotsava and Adhyayanotsava. Dhanurmasotsava celebrates Andal's attempts to marry Ranganatha, a form of Vishnu. She observed tapas (self disciplined meditation) for 30 days before merging herself with him. Those 30 days are celebrated for the entire month of Margashira by a special ritual at the Andal shrine. In Adhyayanotsava (study festival), the deity is conducted to the assembly hall where he is worshipped for 20 days. The 4000 verses of the Tamil text Naalayira Divya Prabhandham is read aloud along with other sacred texts, which lends the festival its name. This festival is divided into two phases: the first phases lasts for the first ten mornings of the fortnight. The eleventh day, which happens to be Vaikuntha Ekadashi, begins the second phase. The deity, seated on a specially made porch, is worshipped in the night during the second phase. Special services suited to each incarnation of Vishnu are offered during this phase.