Shiva (Hebrew: שבעה, literally "seven") is the week-long mourning period in Judaism for first-degree relatives: father, mother, son, daughter, brother, sister, and spouse. The ritual is referred to as "sitting shiva". Immediately after burial, people assume the halakhic status of "avel" (Hebrew: אבל; "mourner"). This state lasts for seven days, during which family members traditionally gather in one home (preferably the home of the deceased) and receive visitors. At the funeral, mourners traditionally wear an outer garment or ribbon that was torn at the funeral in a ritual known as keriah. This garment is worn throughout shiva.
The word "shiva" comes from the Hebrew word shiv'ah, which literally means "seven". The tradition was developed in response to the story in Genesis 50:1-14 in which Joseph mourns the death of his father Jacob (Israel) for seven days.
The Hebrew word "shiva" means "seven", and the official shiva period is seven days. The day of the funeral is counted as the first day of shiva, even though the practice does not begin until after the mourner(s) arrive at the designated location following the funeral. On day seven, shiva generally ends in the morning, following services. On Shabbat during the week of shiva, no formal mourning takes place, but the day is counted as one of the seven. Sometimes, a minyan with a Torah reading will take place at the mourner's house.
If the first day of a Yom Tov (holy days which includes Rosh Hashanah, Yom Kippur, Sukkot, Passover, and Shavuot) occurs during shiva, the shiva ends, regardless of the number of days that have already been observed. Even if a Yom Tov begins at nightfall on the day of the funeral, the remainder of shiva is cancelled.