The day in each month in which the full moon occurs, it is known as Purnima (also called Poornima, Pournima). Purnima May 2016 date is May 21, 2016. The Purnima time begins from 12:42 AM on May 21, 2016 and ends at 02:44 AM on May 22, 2016. Purnima Vrat is on Saturday, May 21, 2016. It is also known as Vaishakh (Vesak or Vesakha) Poornima and Buddha Purnima.