Yud Zayin Be'Tammuz This year the Fast of the 17th Tammuz falls on Sunday, July 8 The Fast of the Fourth Month There is another tradition in the Mishna that associates the 17th Tammuz with the fast mentioned by the prophet Zechariah as the "Fast of the Fourth Month" (see Ta'anit 4:8): According to this interpretation, the 17th Tammuz will be transformed in the messianic era. The day shall be "joy to the House of Judah, and gladness and cheerful feasts." Since the reference to this specific fast was made by a post-exilic prophet, this appears to mark the beginning of a series of fixed-fasts designated to the commemoration of critical events associated with the destruction of the Temple. Customs The fast of 17th Tammuz is observed only from the break of dawn. The sick and expectant or nursing women can observe the fast with lenience. One who is ill need not fast at all. Those permitted to eat should still refrain from eating meat, luxurious food and drink. Special additions to the prayers are added during the day. For more on 17 B' Tammuz read this article by Shimshon Raphael Hirsch!