Galdan Namchot

Galdan Namchot is Tibetan, which means to offer five kinds of things (incense, flowers, lamps, water, and fruits) to Buddha. It commemorates the birth & parinirvana (death) of Je Tsongkhapa, the founder of the Gelug Sect of Tibetan Buddhism, who passed away and attained Nirvana on October 25 of the Tibetan calendar in 1419. So people designated this day and also call it Tsongkhapa Butter Lamp Festival in honor of the master. This festival is often celebrated in Tibet, Mongolia and Ladakh. In 2023, Galdan Namchot falls on Dec 7.
https://www.greattibettour.com/festivals/galdan-namchot.html