Chaturthi is the fourth Tithi of each lunar fortnight, sacred to Lord Ganesha. Krishna Chaturthi (also called Sankashti Chaturthi) falls in the waning moon phase and is observed with fasting and moonrise-based Ganesh Puja. Shukla Chaturthi in the waxing phase is called Vinayaka Chaturthi. The most celebrated Chaturthi is Ganesh Chaturthi (Bhadrapada Shukla Chaturthi), the grand 10-day festival. Monthly Sankashti Chaturthi vrat involves fasting until moonrise and is believed to remove obstacles.