The Ninth of Av, fast commemorating the destruction of the two Temples https://www.hebcal.com/holidays/tisha-bav?utm_source=js&utm_medium=icalendar

Shabbat before Tish'a B'Av (Shabbat of Prophecy/Shabbat of Vision) https://www.hebcal.com/holidays/shabbat-chazon?utm_source=js&utm_medium=icalendar