Here, the Lord gives a clear answer to the question asked by the messengers from Bethel (Zechariah 7:2–3).
The early summer fast remembered when Jerusalem's walls were breached (2 Kings 25:3–4; Jeremiah 52:6–7). The midsummer fast mourned the burning of Solomon's temple (2 Kings 25:8–10; Jeremiah 52:12–14). The autumn fast marked the assassination of Gedaliah, the governor of Jerusalem (2 Kings 25:22–25; Jeremiah 41:1–3) or the day of atonement (Leviticus 23:26–32). The winter fast recalled the start of the siege of Jerusalem (2 Kings 25:1; Jeremiah 52:4).
The fasts will become feasts when God restores Israel and shows His glory to the nations (Isaiah 65:18–19).