What day is April 15?

Qingming [the 15th day of the fourth lunar month]

"Fifteen days after the vernal equinox, the bucket refers to Ding, which is used for Qingming. When everything is clean and bright, everything is clean and bright when it is covered, hence the name." Among the 24 solar terms in a year, people pay special attention to Tomb-Sweeping Day on April 5th. The custom of sweeping graves and offering sacrifices in Tomb-Sweeping Day was inherited from the Han Dynasty. After that, the popularity of the people lasted for two thousand years. On this day, filial children and grandchildren of every family will go to the suburbs to worship their ancestral graves, cut graves, add soil to the graves, and clean them up. In modern times, filial sons and grandsons may not necessarily observe Tomb-Sweeping Day's visit to Tomb-Sweeping Day on this day. Some will pay homage a few days before the festival, and some will pay homage a few days after the festival, but generally speaking, it is just Tomb-Sweeping Day's grave-sweeping.

April 15th of the lunar calendar is a traditional festival of Tibetan Buddhism, Amitabha!

Buddha's Nirvana Day: In China, it is generally believed that February 15 is the Buddha's Nirvana Day, April 8 is the Buddha's birthday, and1February 8 is the Buddha's Enlightenment Day. Some countries regard the full moon day in May of the Gregorian calendar (equivalent to April 15 of the China lunar calendar) as a Buddhist festival, and believe that the birth, enlightenment and nirvana of the Buddha are all on this day.