Significance
Karva Chauth is a beloved festival in which married women observe a rigorous waterless (nirjala) fast from sunrise to moonrise, praying for the long life and well-being of their husbands. Unmarried women sometimes keep it for a desired partner.
It celebrates marital love and devotion, and its rituals of sighting the moon through a sieve have become iconic.
Rituals
Women rise before dawn to eat sargi, keep a strict fast through the day, dress in bridal finery, and gather in the evening for the Karva Chauth katha, passing the decorated karva (pot). At moonrise they view the moon and then their husband through a sieve, and the husband offers the first sip of water and food.
How the date is fixed
Karva Chauth falls on the Chaturthi of the Kartika Krishna paksha; the fast is broken at moonrise, so the moonrise time is shown above for your location.