When does the seven sevens after a person's death start to be counted?

When someone dies in the family, many places have the custom of burning the first seven days of mourning, and the way and etiquette of burning the first seven days of mourning are slightly different in each place. The seven sevens after a person’s death, from which day do they start counting?

The Seven Sevens after a Person's Death

[The first seven days]: The first seven days means that during this time, the deceased can still recognize people. He can remember who participated in the burning seven days sacrifice, and will look forward to his coming every seven days thereafter.
【Erqi】 : Erqi is a sacrificial activity that only sons can participate in;
【Sanqi】 : Sanqi is a ceremony that is usually attended by children, neighbors, and important relatives. Because there are many people participating, the host family needs to entertain guests after the ceremony.
【47】 ： 47 is usually attended by only children;
[Wuqi] : Wuqi is the biggest one, which requires many people to attend. Basically, everyone who can attend should attend. Children need to offer sacrifices, and this requires a grand banquet for guests.
【Six Seven】 : Six means remaining seven, which means that if you have participated in the previous seven, you cannot participate in this one;
[Seven Sevens] : The Seven Sevens is also known as the Duan Qi, and only children, relatives, and neighbors can participate.

From which day

1. "Burning sevens" means counting from the day of death of the deceased, with every seven days being a memorial day, called the first seven, second seven, third seven, fourth seven, fifth seven, sixth seven, and "the last seven (breaking seven)", totaling forty-nine days. According to folklore, people have three souls and seven spirits. One year after death, one soul dissipates, one spirit leaves after seven days, the soul is gone after three years, and the spirit is gone after seven days. So there are seven periods and three years to celebrate, and some even have a hundred days or an anniversary.
2. Among them, the "third seven" and "last seven" are the most important. The soul of the deceased will return home on the "first seven days", which is the "first seven days" night of the soul returning. The family should prepare a meal for the soul of the deceased before the soul returns, and must leave afterwards. You can no longer take care of things after 21 days for the deceased, which is the origin of the saying “no matter what”; between 35 and 49 days, they officially enter the cycle of reincarnation. The period from the time a person dies to the time the soul enters reincarnation is what Buddhism calls the "bardo body."
3. There is another saying that the King of Hell will interrogate the soul of the deceased every seven days within 49 days from the date of death, so the "seven periods" are also called "seven disasters." On the first seven days, a spirit tablet is set up at home, incense is burned, candles are lit, and wine and food are offered as memorial services. On the remaining six or seven days, paper money is burned at the grave.