The story
From its former Chinese name 掃墳節 /扫坟节 (Sǎofénjié, “Sweep-Tomb Festival”), from the traditional act of cleaning one's family grave with willow branches during the holiday.
Etymology from Wiktionary, CC BY-SA 4.0.
Tomb Sweeping Day
Today it means: An annual Chinese holiday on the first day of the fifth solar term in the traditional Chinese lunisolar calendar (April 4 or 5), during which families gather to honor their ancestors and clean their tombs. The festival is also associated with the consumption of qingtuan. Full definition →