In Zechariah the fast days are not connected to specific days but to specific months. Unlike the other fast days connected to the Churban, were Asara B’Tevet to fall on Shabbos we would fast on Shabbos.
The purpose of a fast is to do teshuva for the events that occured on that day. If Asara B’Tevet is connected to the First Temple, what is its lesson for us post-churban Bayit Sheni?
Recorded at OU Israel’s L’Ayla Rosh Chodesh Women’s Event