What are the fasts mentioned in Zechariah 8:19?

This scripture mentions fasts that were held on the fourth, fifth, seventh and tenth months of the year. These fasts were proclaimed by men of Judah to commemorate four terrible events that fell upon the Jews during the days of the final defeat by the Babylonians.

The fasts depict the following events (listed chronologically):

Tenth month: Jeremiah 52:4-5 records the account of King Nebuchadnezzar setting up the final siege against Jerusalem in the tenth month during the ninth year of the reign of Zedekiah.

Fourth month: Jeremiah 52:6-7 records the Babylonians breaking into Jerusalem due to the city being so weakened by famine after sixteen months of the siege. This occurred during the fourth month of the eleventh year of the reign of Zedekiah.

Fifth month: In Jeremiah 52:12-14, Nebuzaradan, the captain of the guard of King Nebuchadnezzar came to Jerusalem with his army and carried away valuables that were in the Temple, burned the Temple and the city, and took away many captives. This event occurred in the following month of the same year that the Babylonians broke into Jerusalem as noted above.

Seventh month: This fast commemorates the tragedy of Gedaliah and those with him at Mizpah being slain by Ishmael and his band of murderers. This account is recorded in Jeremiah 41:1-3. Gedaliah had been appointed governor by the Babylonians in the wake of the captivity to oversee those left behind to manage the land.

When Israel is once again obeying God’s laws and His way of life, He will change these man-appointed fasts. Zechariah 8:19 states that these days of sorrow “shall be to the house of Judah joy and gladness, and cheerful feasts; therefore love the truth and peace.” Verses 20-23 show that Judah will follow God and be blessed abundantly. They will no longer need to commemorate these horrific events.