According to the book "Vietnamese traditional vow" - the cultural and information publishing house, the old grandparents chose Tiet Thanh Minh as the day of cutting the grass on the grave and embankment on the grave (algae). Because this day the weather turns to warm, rains more, the plants are better than the grave, can make the grave landslide, so it is necessary to cut the grass, apply more soil to the grave.
During the time of going to Thanh minh to the c tomb, to commemorate their ancestors and deceased relatives, people can walk around and see the lush grass and trees, so it is also called "Dap thanh".
On this day, families often hold New Year's Eve offerings at home and outside the tomb to worship and commemorate their deceased ancestors andors.

Depending on each locality and the conditions, each family celebrates the offering tray differently, it can be vegetarian or salty. Let's refer to the Lunar New Year worship tray at home and outside the tomb:
Opening of the Lunar New Year worshiping Mass at Home
- Fragrance
- Areca nut, gold
- Meat alcohol (s pig's feet, boiled chicken or a portion of pork leg thinly sliced)
- Fruits
- Stewed sticky rice, burned
- Salted rice, votive paper
- Bottle of water...
Thanh Minh Khu Doan Tomb
- Gold money, five-digit gold card, paper clothes
- Fruits
- Areca nut
- Clean water, white wine
- Lamps
- Vegetarian or salty offerings (boiled meat, pig's feet, whole or braised chicken...).
In addition, families can offer a tri set of pork, a shrimp (or crab) and an egg (chicken or duck).
Usually, families will worship the Lunar New Year outside the tomb first, inviting grandparents and ancestors to return home with their children and grandchildren. During the ceremony, the children and grandchildren wholeheartedly bowed, did not laugh or joke, and talked to show respect for their ancestors.
In addition, while cleaning, clearing, and filling the grave, incense must be burned in advance, and no trampoline must be trampled on the grave.