Laws of the Three Weeks
During the three weeks between the 17th of Tammuz until after Tisha B’Av, the custom is to observe some aspects of mourning over the destruction of the Holy Temple. The observance intensifies as Tisha B’Av approaches.
(The following is according to the Ashkenazic custom, for the Sephardic custom please consult an appropriate rabbi.)
- Weddings should not be performed during this period.
- Engagements may take place with a meal until the 1st of Av. From the 1st of Av until after Tisha B’Av they may take place with refreshments only.
- Dancing and playing or listening to music is prohibited. A musician who earns his living by playing for non-Jews may do so until the 1st of Av.
- The custom is to refrain from reciting the blessing "sh’hecheyanu" on new garments or fruit, except on Shabbat. Pregnant women or ill people who need the fruit may eat it normally. New garments that don’t require this blessing may be purchased and worn until the 1st of Av.
Haircuts, Shaving, Cutting Nails
- The custom is to refrain from taking a haircut, including the beard. An adult may not even give a haircut to a child.
- Trimming the mustache is permitted if it interferes with eating. Combing and brushing the hair is permitted.
- A person who usually shaves daily (in a permitted manner) and would suffer business or financial loss by not shaving, may do so until the 1st of Av, or at most until the Friday before Tisha B’Av. In any case, one should consult a competent rabbi.
- A married woman may remove hair that protrudes from under her hair covering, and facial or bodily hair that may be unnattractive to her husband.
- Cutting the nails is permitted until the Friday before Tisha B’Av. Even then it is permitted for a woman before immersion, or for a man as well, in honor of the Shabbat (for example if Tisha B'Av is on Shabbat and postponed to Sunday, or if it is on Sunday itself).