Tisha B’av is one of only two major fasts in the Jewish calendar, the other being Yom Kippur. It is a day of mourning where we refrain from eating and drinking.
The first nine days of the Jewish month of Av are days of acute mourning. The nine days, as they are known in the Jewish calendar are so sad, that Jewish people historically have refrained from eating meat (or chicken) and drinking wine during this time. These nine days lead us into the height of our mourning with a fast day on the ninth of Av, which commemorates the destruction of the second temple, by the Romans, in 70 CE.
Tisha B’av literally means the 9th of the Hebrew month of Av, it is usually falls in July or August.
The nine days leading up to Tisha B’av are also days of mourning when we do not eat any meat.
The final meal before Tisha B’av (“Seudah Mafseket”) is eaten in a state of "mourning", sitting on the floor, eating a piece of bread and a hardboiled egg with some ashes.
The reason such foods are eaten by mourners is to remind us that death and mourning is part the circle of life. Just as bad times come around in our lives, so too good times are sure to follow.
On the eve of Tisha B’av we read the book of Eicha, Lamentations, and usually do so in the dark by candlelight sitting on the floor. The next day we also sit on the floor until after midday when the mood begins to lighten and we can begin preparing for our break the fast meal.