Sankashti Chaturthi is the fourth day of Bahula Paksha of every month of Lunar Calendar. Sankashti Chaturthi is the fourth day of the waning phase of the moon in every month.
If Sankashti Cahturthi falls on a Tuesday it is known as a Angarika Chaturthi or Angarika Sankashti Chaturthi or Angarika Sankata Hara Chaturthi. Angarika Chaturhti is considered auspicious as it has both the Chaturhti or Chaviit thithi and Tuesday, the favorite day of Lord Ganesha.Angarika Chaturthi is considered to be very auspicious for the devotees of Lord Ganesh. Devotees observe the Angarika Chaturthi fast or Vrat. The fasting or Vrat is the same for Angarika Chaturthi as for the Sankashti Chaturthi. Only the returns are many fold on an Angarika Chaturthi when compared to Sankashti Chaturthi.