Gai Jatra is a hindu festival mostly celebrated in Kathmandu valley on first day (Pratipada) of the month of Bhadra (August-September) of the Lunar calendar. This festival is celebrated to commemorate the death of dear one during the year. Members of decesead family participate in a procession through the street of Kathmandu leding a cow. If cow is not available, kid dressed in cow outfit is considered a fair substitute.
According to the historic evidence, Gai Jatra date back to ancient Malla period. When King Pratap Malla lost his son, his wife, the queen, remained grief-stricken. The king was very sad to see the condition of his beloved queen. The king, in spite of several efforts, could not lessen the grief of his wife. To show his wife that death is a natural part of life, he called on people for a carnival if someone has died in their family. Many people came which showed the queen that it is not only her son had died somebody has died in every family in this festival.