Sankashti Chaturthi (संकष्टी चतुर्थी) also known as Sankata Hara Chaturthi is an auspicious day dedicated to Lord Ganesha. This day is celebrated in every Lunar month or Hindu calendar month on the fourth day of Krishna Paksha (dark lunar phase).
This day is considered to be very auspicious and it is believed that people who observe Sankashta Chaturthi Fast or Sankashta Chaturthi Vrat get rid of all difficulties and obstacles in their life.
As told you earlier, Lord Ganesha is widely revered as the Remover of Obstacles for which he is known as Vighnaharta (विघ्नहर्ता), Vighnavinashaka (विघ्नविनाशक) and Vigneshwara (विघ्नेश्वर).
People observing Sankashti Chaturthi Vrat, observe a fast for the entire day which is broken after taking darshan of Moon followed by worshipping of Lord Ganesha.
When Sankashti Chaturthi falls on Tuesday, it is known as Angaraki Chaturthi (अंगारिका चतुर्थी) and it is considered highly auspicious Sankashti Chaturthi day. It is believed that a person who keeps a fast on Angaraki Sankashti Chatutrhi gets the benefit equal to that gained by observing Sankashti Chaturthi fast throughout the year.