Halachos of the Three Weeks
The 17th of Tammuz (July 5th) through the 9th of Av (July 26th) is referred to as the three weeks.
This has historically been a tragic time for the Klal Yisroel. The Mishna relates that 5 tragic things happened to us on the 17th of Tammuz.
The five things that happened on the 17th of Tammuz are:
1. Moshe broke the luchos.
2. The daily Tamid offering stopped being offered in the Beis Hamikdash.
3. The walls of Jerusalem were breached.
4. Apostomus burned a Torah.
5. An idol was placed in the sanctuary.
As a result of these tragedies, the Klal Yisroel have accepted upon ourselves certain restrictions.
We start off with the 17th of Tammuz.
This is a fast day. The fast starts at dawn, and goes until nightfall. It is permissible to wash hands, shower, and brush teeth.
During the 3 weeks it is forbidden to get a haircut, shave, listen to music (some poskim permit music while exercising) and get married. Sefardim are permitted to do all of the above.
If a person will lose his job, or lose potential income, he may shave.
The brocha of shehechiyanu should not be said. New clothing may be purchased, provided that it does not cause one to say the brocha (shehechiyanu is only said of the new item [clothing or otherwise] if it causes great simcha).
The Mishna Berura writes that one should refrain from buying a new home, unless there is great need.