There is love in Av! Tu BeAv falls on the 15th of Av (in fact, that is what the name means). More than one source notes that many holidays fall on the 15th of a month - during the full moon: Passover, Sukkot, Tu Bishvat.
During the days of the Second Temple, Tu BeAv was known as a matchmaking day. Then it lapsed into obscurity until modern times. In the Mishnah, Rabban Shimon ben Gamliel is reported to have said:
There were no better days for the people of Israel than the 15th of Av and Yom Kippur. On these days the daughters of Jerusalem go out in borrowed white garments in order not to shame any one who had none. All these garments required immersion. The daughters of Jerusalem come out and dance in the vineyards. What would they say? Young man, lift up your eyes and see what you choose for yourself.
The festival was also celebrating the grape harvest. Can you imagine borrowing white clothing and going out to celebrate grapes? Rather, can you imagine lending a white frock for use around grapes?
In Nehemiah 13:31 the bearing of wood to the Temple to celebrate first fruits is noted. Josephus called it the Feast of Xylophory (bearing wood). This task would be completed on Tu BeAv.
Between those days and the middle of the 20th century, Tu BeAv was ignored, except to eliminate saying Tahanun during morning prayers on that day. Nowadays in Israel, there is singing and dancing on the evening of Tu BeAv. People get ferpitzed and go out on the town. The next day is, of course, a work day. The day is not celebrated with any liturgy or extra shul going or special religious rituals.
It is called חג האהבה, Hag Ha’ahavah. Ahavah (אהבה) in Hebrew means “love.” The root of the word is אהב - to give. To love is to give, selflessly. It is a good day for proposals, weddings, and romance. The holiday begins the evening of July 23rd this year.
And the young ones might sing, “Shine on, shine on Harvest Moon, up in the sky….”