The Shulhan Aruch rules that it is permissible to get married and make weddings from Shiba Asar Be’Tammuz until and not including Rosh Hodesh Ab. In his view, weddings are forbidden only during the nine-day period from Rosh Hodesh Ab through Tisha B’Ab. The practice of the Ashkenazim, however, following the ruling of the Rama (Rabbi Moshe Isserles of Cracow, 1525-1572), is to forbid weddings throughout the period of the Three Weeks, from Shiba Asar Be’Tammuz through Tisha B’Ab.
Generally speaking, Sepharadim follow the rulings of the Shulhan Aruch, and indeed, both Hacham Ben Sion Abba Shaul (Israel, 1923-1998), in his work Or Le’sion (vo. 3), and Hacham Ovadia Yosef, rule in accordance with the Shulhan Aruch’s position, allowing weddings until Rosh Hodesh Ab. Nevertheless, the accepted custom among the Syrian Jewish community is not to make weddings during the Three Weeks. The reason likely has to do with people’s natural desire to get married in an auspicious time that bodes well for the future of the marriage, and the period of the Three Weeks is one which is characterized by calamity and mourning. Hacham Ovadia opposed the practice of delaying weddings until after the Three Weeks, given the concern that delaying marriage can result in improper thoughts and the like. Nevertheless, it is important to follow communal customs, as the Sages taught us, "Ve’al Titosh Torat Imecha" – "Do not abandon the teaching of your mother," referring to the customs passed down to us from our mothers. Members of the Syrian community should thus not get married during the three-week period from Shiba Asar Be’Tammuz through Tisha B’Ab, in accordance with the custom that has been observed in the community for many years.
It is permissible, however, to make an engagement during this period, until and not including Rosh Hodesh Ab, provided that there is no music or dancing. The Shulhan Aruch would allow getting engaged even during the Nine Days, and even on Tisha B’Ab itself, but according to our custom, this is permissible until and not including Shiba Asar Be’Tammuz.
Summary: The accepted practice of the Syrian Jewish community is to forbid weddings during the three-week period from Shiba Asar Be’Tammuz through Tisha B’Ab. Engagements are allowed from Shiba Asar Be’Tammuz until and not including Tisha B’Ab.