Tu Beshvat, the 15 th day of the Hebrew month of Shvat, is first mentioned in the first mishnah of the Talmudic tractate of Rosh Hashana as the New Year for trees. This has halachic implication with regards to calculation of the three years of orlah , during which all fruits of the tree are forbidden, the fruits of the sabbatical year, and the calculation of tithes. According to Kabbalistic concepts, this day has significance as the time of year when the winter is beginning to pass.
Light is good and redemption, while darkness is regarded as bad and misfortune.
The first was white wine symbolizing the lifeless slumber of the winter. The second was a mixture of both red and white while the majority is white symbolizing the arising of the creation from the slumber of the winter. The third had more red than white, and the fourth was completely red. The white wine symbolizes the pale light of the moon which is visible during the long nights of the winter, while the red wine is the strong light of the sun.