Udyapan is strictly followed by many Hindu communities. It is the ritual performed on the day of the formal ending of vrats like Solah Shukravar Vrat, Solah Somavar Vrat and all important fasting that are observed for a period of year or month. The original Udyapan as per Hindu scriptures vary for each vrat but it is no longer strictly followed by majority of Hindus as it is almost impractical today. For example for most Udyapan it is asked to invite 21 brahmins and feed them.
Today, people perform Udyapan as per their capacity. Some Hindus invite a priest and do a big puja and feed friends, relatives and neighbors. In such pujas all the rituals and how to end the vrat are explained by the priest.
Some perform pujas and prayers and feed the poor on the day. They also visit the temple of the deity to whom the vrat was kept.
Another simple method that is gaining popularity is to invite a couple and feed them.