If one’s mustache is getting in the way of his eating, he may trim it until the week of Tisha Be’Av. (See below)
If one needs to shave (in a permissible way) for business reasons, there is room for leniency during the Three Weeks and the beginning of the Nine Days, but not during the week of Tisha Be’Av. One should discuss this with their rabbi.
One should also not give haircuts to their young children at this time.
If a child’s third birthday falls during the Three Weeks, the upsherinish (first haircut) should be postponed until after Tisha Be’Av. Nevertheless, the chinuch of the young boy in terms of other mitzvot should begin on his birthday. E.g, putting on tzitzit, saying the morning brachot etc.
If a woman needs to cut her hair for reasons of modesty, she may do so even during the Nine Days.
Generally, one should refrain from cutting bodily hair at this time, but, if necessary, a woman may pluck her eyebrows or wax her legs until the week of Tisha Be’Av.
Combing hair is permissible even in the week of Tisha Be’Av.
There is room for leniency if a young lady needs to take a haircut in preparation for a shidduch date up until the week of Tisha Be’Av.
A father of a baby who is having a brit milah may take a haircut on the day of the brit in honor of the brit. The same applies to the mohel and/or sandek.
One whose aveilut (mourning period) ended during the Three Weeks but before Rosh Chodesh Av, may take a haircut at that time. Some are lenient until the week of Tisha Be’Av.
