The event (Sankashti Chaturthi) takes place in every lunar month as per the Hindu Samwat calendar, and when this Chaturthi falls in the month of Magha, then it is called as Dwijapriya Sankashti Chaturthi.
People offer special prayers and also observe fasting, which is known as Dwijapriya Sankashti Chaturthi Vrat by the devotees.