When Is Tisha B'Av In 2025. Tisha b'av primarily commemorates the destruction of the first and second temples, both of which were destroyed on the ninth of av (the first by the babylonians in 586 b.c.e.; In particular, tisha b’av commemorates the destruction.
Since 1993, the chofetz chaim heritage foundation creates a yearly tisha b’av event for one reason: With an eye to the future, we also learn about the third temple, which is yet to be built.