Today is Tu 'Be Av, the Jewish Valentine's Day. In searching for a description of how Jews in Arab lands celebrate this day, I came across an alternative explanation from Shlomo on the Tunisian-Jewish blog Harissa: : it's all about cutting trees, breaking up axes and serving the Temple in Jerusalem.
Why is this festival so important?
At the time of the Beit Hamikdash (the Temple in Jerusalem), there was a need to keep a fire burning on the altar. Trees were cut down for this purpose from the month of Nissan (the month of the festival of Passover) until 15 Av, because it is the hot season and the wood dried out well. The wood had to be free of worms. But from the 15th of Av, it is less hot and there is more a risk that the wood might contain worms, which would make it unfit for purpose. Tu Be'Av was therefore the date when it was no longer necessary to fulfil the great mitzvah which consisted in preparing the wood of the altar, and so this day became a day of celebration.
But this reason seems obscure. How does finishing this work justify such great joy? Tu Be'Av is the opposite of Tisha B'Av.
Tisha B'Av is the day of mourning par excellence, while Tu B'Av is the day of joy par excellence, and both of them are related to the Beit Hamikdash: mourning the 9th of Av because of the destruction of the Temple, the joy of the 15 Av linked to its construction and its existence.
Jews can no longer serve a temple that is destroyed, while cutting wood, in contrast, gives the temple its entire raison d'etre: to be the house of God, available to conduct the service. This is why the joy was so great that day. (...)
According to this explanation, we may understand why this day of Tu Be'Av is called "yom tevar magal", "the day the axes is broken"; because on that day, the axes that had been used to cut trees were broken up.
Read post in full (French)