Chapter 122 – The Interval Between the Seventeenth of Tammuz (fourth month of the Jewish year) and the Ninth of Av (fifth month of the Jewish year)
122.1) It is customary to observe some rules of mourning from the beginning of the seventeenth of Tammuz (fourth month of the Jewish year) until the ninth of Av (fifth month of the Jewish year).
122.2) Do not say the benediction Sheheheyanu (Who hath kept us in life) during these days.
122.3) Do not have your hair cut and do not cut your children’s hair.
122.4) You may trim a mustache if it interferes with eating.
122.5) Trimming of nails is permitted in some circumstances.
122.6) Certain Scriptures are read on the three Sabbaths occurring during this time. (See source for details, or consult a rabbi.)
122.7) Mirth should lessen as the month of Av arrives.
122.8) Abstain from wine and meat during the nine days from the New Moon until the ninth day of Av.
122.9) Do not wash clothes during these nine days.
122.10) Do not have new shoes or clothes made during these nine days.
122.11) Women should not arrange threads for weaving during these nine days.
122.12) Do not bathe during these nine days. Some exceptions are listed in the source.
122.13) If the New Moon occurs on a Friday and you are accustomed to bathe on Fridays, you may do so.
122.14) A mourner in his thirtieth day of mourning on the eighteenth day of Tammuz (fourth month of the Jewish year) may have his hair cut.
122.15) The person who carries an infant in for a circumcision during the nine days may not wear his Sabbath clothes.
122.16) White linen may be put on.
122.17) During the nine days, on a Sabbath, call up a rabbi who understands the spirit of the lament to read the maftir.