(“Between the Straits”), in Judaism, a period of mourning running from the 17th day of Tammuz, the fourth month of the Jewish religious year, to the 9th day of Av (Tisha be-Av), the fifth month (variously, about June to August). The observance commemorates the days between the first breaching of the walls of Jerusalem in 586 BC by Babylonian troops under Nebuchadrezzar to the subsequent destruction of the First Temple of Jerusalem. Marriages and haircuts are forbidden during the Three Weeks. The nine days of Av are observed with special intensity: meat and wine are forbidden except on the Sabbath, the blessing of the New Moon is omitted, and prophecies of doom from Jeremiah and Isaiah are read in the synagogue on the three Sabbaths that fall within this period. The period ends with a 24-hour fast.