This is because the darkest events in Jewish history occurred during the first week and a half of this month, particularly The Nine Days which culminate in Tisha B'Av, the 9th of Av.
Hal ini disebabkan sejumlah tragedi paling pahit dalam sejarah Yahudi terjadi dalam minggu pertama sampai pertengahan bulan ini, terutama "Sembilan Hari" (The Nine Days) yang berpuncak pada Tisha B'Av, tanggal 9 Ab.