The fast day of Tisha B'Av, the 9th of Av, is one of the two 24-hour fast days in the Jewish calendar, the other being Yom Kippur. In a sense it is the "low point" of the Jewish year. Despite this, the tradition is that Mashiach is born on Tisha B'Av. Therefore, turning the tragic events of Tisha B'Av into ultimately a day of hope, prayer and anticipation for redemption and rectification.