Margashirsha Purnima vrat date December 2016
The day in each month in which the full moon occurs, we know it as Purnima (also called Poornima, Pournima). Purnima December 2017 time begins from 12:57 AM on December 2, 2017 and ends at 09:17 PM on December 3, 2017. Purnima Vrat is on Sunday, December 3, 2017. It comes in Margashirsha month, so we call it Margashirsha purnima.
Lord Dattatreya was born on the day of Purnima in the Margashirsha month. So Margashirsha purnima is also celebrated as Dattatreya Jayanti