Sankata Hara Chaturthi is observed on the Krishna Paksha Chaturthi (fourth day of the waning phase of the moon), of every month in the Hindu calendar. This day is even more auspicious, especially if it falls on a Tuesday or Friday.
The Sanskrit word “sankashti” means deliverance from troubled or difficult times, so worshipping Lord Ganesha on this day means you’ll be blessed with peace and prosperity in the coming times.
The Sankata Chaturthi that falls before a fortnight (15 days) of Ganesh Chaturthi is very auspicious to worship Lord Ganesha, and known as Maha Sankata Hara Chaturthi.