Kasumba Shashti is an auspicious vrata, observed on Shukla Paksha Shashti in Ashada Month according to Hindu calendar. In 2018, Kasumba Shashti date is July 18.
Kasumba Shashti is also celebrated as Kumara Shashti, a festival dedicated to Lord Kumara swamy (Skanda, Muruga, Kartikeya, and Subramanya).
Kumar Sashti is an important festival of Nepal. Most of the devotees observe fasting on Kumar Sasthi day.