Av is the eleventh month of the civil year and the fifth month of the ecclesiastical year on the Hebrew calendar. It is a month of 30 days, and usually occurs in July–August on the Gregorian calendar.
Francesco Hayez, The Destruction of the Temple of Jerusalem, 1867. The 9th of Av, Tisha B'Av, is a fast commemorating what has been called the saddest day in Jewish history, which is when the Holy Temple was set aflame.
Remembrance of the Destruction, showing women reading the Book of Lamentations, painting by Leopold Pilichowski (1925)