The Mishnah tells us that: ‘No days were as festive for Israel as the 15th of Av and Yom Kippur.’ …What is Tu B’Av [and in] which way is it equivalent to Yom Kippur?

Our Sages explain: Yom Kippur symbolizes God’s forgiving Israel for the sin of the Golden Calf in the desert, for it was on that day that He finally accepted Moses’ plea for forgiveness of the nation, and on that same day Moses came down from the mountain with the new set of tablets.

Just as Yom Kippur symbolizes the atonement for the sin of the Golden Calf, Tu B’Av signifies the atonement for the sin of the Spies [which caused the decree] by God that the nation would remain in the desert for 40 years, and that no person 20 or older would be allowed to enter Israel. On each Tisha B’Av of those 40 years, those who had reached the age of 60 that year died – 15,000 each Tisha B’Av. This plague finally ended on Tu B’Av.

Six positive events occurred on Tu B’Av. [See the full article to learn more about these events].

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To this day, we celebrate Tu B’Av as a minor festival. We do not say Tahanun on that day, nor are eulogies rendered…

Beginning with Tu B’Av, we start preparing ourselves spiritually for the month of Elul, the prologue to the coming Days of Awe…