That festival is Karwa Chauth. It is a Hindu observance where many married women fast from sunrise until moonrise, then break the fast after seeing the moon.

Quick Scoop

  • Name: Karwa Chauth.
  • When: It falls on the fourth day after the full moon in the Hindu month of Kartik, usually around October or November.
  • Practice: Women traditionally avoid food and water until they sight the moon.
  • Meaning: It is commonly linked to prayers for the husband’s well-being and long life.

Small note

In some regions, similar full-moon fasting traditions exist, but the one most people mean with “women fast all day until they see the moon” is Karwa Chauth.

TL;DR: Karwa Chauth is the festival you’re describing.