Karwa Chauth falls on Krishna Paksha Chaturthi or the fourth day of moon's waning phase in the month of Kartik. This year it would be celebrated on 4th November.
The year on Karwa Chauth the moon is expected to rise at 08:27 PM.Here's all that you need to know about Karwa Chauth Mahurat, Puja Vidhi, Vrat, Sargi and Shringhar
A puja is performed in the evening, usually in a community gathering, wherein the katha is read out. Here is the puja muhurat time as well as moonrise time across India.