The date for Karwa Chauth vrat October 8, 2017. Karwa Chauth is a fast which begins in the morning and ends at night after the Moon is visible in the sky. The Moon rises late on Kartik Krishna Paksha Chauth, so it is a very difficult and strict fast. Karwa Chauth fast is observed on Kartik Krishna Paksha Chauth by the wife,who having well dressed up with her fancy jewellry and makeup, performs Puja and prayer for the long life and well being of her husband. Fast is ended after sighting of the Moon of the Chauth in different cities.