We found from their whiteboard yesterday: Sarva Amaavaasai (Polaala Amaavaasai), but we could not go for it.
Polala Amavasya (also known as Polamba Vratham or Shravana Amavasya) is a traditional Hindu festival observed on the new moon day (Amavasya) of the Shravana month in the Telugu calendar; Dedicated to Goddess Poleramma (or Pochamma).