Janai Purnima is a culture which is celebrated among the Nepalese. Janai means sacred thread, and Purnima is full moon day, thus it is Janai festival in the full moon day of Shrawan month of Bikram Sambat calendar.
A day before the janai purnima people who are wearing janai take a good bath and make themselves clean by shaving , cutting hair. They undergo partial fasting, eating one meal a day but there is also exception in the food. The food shouldn't contain garlic, onion or meat. They prefer to stay pure.
Usually people in the morning go to the river and take a 3 dips, change the janai by breaking old one. But in the cities area pandit come to their house and helps them to change the janai by giving them new pure threads.
"Janai purnima as Kwati purnima or Gunhi Punhi"
In Newari janai Purnima is also called Gunhi Punhiand the special food of that day is Kwati thus, this day is also called Kwati Punhi, where Kwati is a soup of different beans and Punhi means the full moon day. Newar people also put the sacred threads around the wrists which are to be taken off on the day of Laxmi Puja, another festival in Tihar.
This festival is very essential religious value among the maternal uncles,nephews,married and unmarried daughters , sisters and their husbands along with their children. Because in this day they all are invited to eat, given some donation as their capacity for efficiency.
In these festival thousands of devotees worship Lord Shiva at Pashupatinath in Kathmandu and Kumbeswor in Lalitpur and take holy dips in ponds and lakes to eradicate their sins. A very great religious fair takes place at Gosaikunda lake in Rasuwa District.Ganga Dhanus Sagar at Janakpur and Tribenidham mela is also observed.
In Janai Purnima Newar farmers offer different food items to frogs. Believing that worshiping the frog, who is considered an agent of the God of rainfall, by making offerings of different food items help to increase the production of crops.
The day before the janai purnima(around 11:45 pm), the newari people put the God in the centre surrounded by the water which is originated in that place(Dhungeydhara). People say that if you worship it your wishes will come true.