Sankata Hara Chaturthi or Sankashti Chaturthi or Sankat Ganesh Chaturthi is observed on the Chaturthi or Chavithi, the fourth day of Krishna Paksha during every month.
Sankatahara Chaturthi which comes on Tuesday is referred to as Angaraki Sankashti Chaturthi. Devotees of Lord Ganesh consider the Sankat Vinayaka vratam as highly auspicious. They observe upvaas on whole day and perform Sankat Ganesh Puja in the evening and break their fast after Chandra darshan (seeing the Moon God).
The significance, spiritual importance and the greatness of Sankatahara Chaturthi is mentioned in the Bhavishya Purana and the Narasimha Purana. Sankashti Chaturthi mahatmya was narrated by Lord Krishna to Yudhistira.
Devotees of Lord Ganesh believe that if a person who observes Sankshta Chathurthi vrat would collect lot of virtues. The person goes directly to the Swanand-loka where he can enjoy the prosperity and blessings of the Lord. There is a strong belief in Hinduism that a person takes seven births before she/he gets Moksha (salvation) but, the person who will do the Sankashta-Chathurthi will go Ganesh loka or Swanand loka directly and his rebirth will be stopped.