What is Tu B'Av?

Answer 1

Tu B'Av is the 15th of the month of Av - which corresponds to August usually. A number of joyous events happened over the years on Tu B'Av: * It was the day the Generation-of-the-Wilderness realized that the sin of the spies had been forgiven, in the year 2488 after creation. * It was the day that the tribes were allowed to intermarry, including orphaned daughters (as per Bemidbar 36:8) once all those who conquered the Land had passed away. * On the same day the tribe of Binyamin were allowed to intermarry with other tribes, after the scandal of Give'ah (as per Shoftim 19 - 21), around the year 2524 after creation. * It was the day that King Hoshea ben Elah removed the blockades that the wicked King Yerav'am ben Nevat had placed on the roads, preventing the Jews from going up to Jerusalem for the Festivals about 75 years earlier, around the year 3040 after creation. * It was the day the Romans allowed those massacred by the wicked Hadrian in Beitar to be buried, some time after he died in 138 (C.E). * It was the day they stopped chopping wood for the altar in the Bet Hamikdash every year, as it marks the end of "summer" (as per Rashi on Breishis 8:22) and the start of the 2 months of "heat". The wood had to be worm free to be used on the altar, and had to be fully dried before the rainy season.

This gave everybody more time for learning Torah - and therefore Tu B'Av is the Joyous Day of Increased Torah Learning.

Source: The Book of our Heritage, Vol 3 page 307-313