What was the date of Diwali in the year 1981?

15 November 1982 was the date of Diwali according to Deepavali.net

Diwali falls on the new moon night (Amavasya) between mid-October and mid-November. Diwali is celebrated for five days according to the lunisolar. It begins in late Ashvin (between September and October) and ends in early Kartika (between October and November).