People from Hanoi travel to the countryside cemeteries to place fresh earth on the graves, pull weeds, replant flowers and repaint the tombs. It's on the fifth day of the fifth lunar month. This is also celebrated in China. It corresponds to the Summer solstice, the time of peak growth. It is thought to be an unhealthy period of time, a time of epidemics.
Vietnamese people pray to avoid epidemics and eat nhng, the larvae of the silkworm.
Vietnamese people believe that on the fifth day of the fifth lunar month, the intestinal worms emerge and that this provides an opportunity to eradicate them by eating green fruit and rice with liquor, called ruou nep. Liquor makes the worms drunk and the fruit will kill them. This is also the time to take a therapeutic shower and rub ones body with mint leaves. People go into the countryside and pick medicinal herbs to dry and store because samples picked that day are believed to cure parasitic diseases. It is also a day of prayer for freedom from crop destroying insects.