Some of the fondest memories of my youth as a student in yeshiva in New York are connected to Tu Bishvat. Although it is a minor holiday in the Jewish calendar, the 15th day of the month of Shvat was a time when I would receive my certificate from the Jewish National Fund for having donated funds to plant a tree in Israel in honor or in memory of those close to me. I also had the experience of participating in a Tu Bishvat Seder with friends of Sephardi origin. As a student at the Hebrew University of Jerusalem, I had a chance to visit the Galilee and see the fruits of the labor of the Zionist pioneers who transformed the 15th of Shvat from its roots in the ancient Jerusalem Temple into the modern Jewish Arbor Day. The genius of the early Zionists was in recognizing that a minor holiday in the cycle of the Jewish year, a holiday associated with tithing and the long-destroyed Temple in Jerusalem, could be given new meaning to Jews in the modern world. According to the rabbis of old, the 15th day of Shvat marked the beginning of the separation of the tithes of fruit, a date chosen for this purpose because most of the annual rain in the Land of Israel falls before then. The fruits of those trees that blossom after Tu Bishvat were considered by the rabbis to belong to another year as far as tithes were concerned, and with regard to the prohibition of using fruit during the first three years of growth. This New Year for Trees was a day on which the rabbis prohibited fasting and on which penitential prayers were not recited in the liturgy. AMONG THE traditions that developed in the world of Ashkenazi Jewry pertaining to the 15th of Shvat was the eating of fruits grown in the Land of Israel. I still remember the luscious taste of the dates from Israel that we ate in school for the holiday. In the domain of Spanish-Portuguese Jews, Tu Bishvat was given even more significance than in the Ashkenazi rite. The Kabbalists of Safed, in the golden age of Jewish mysticism in Israel in the 16th century, embellished on the liturgy by harnessing a Pessah-like Seder to the Tu Bishvat ritual. Whether this was a proto-Zionist expression or a quasi-messianic hope that Temple tithing would soon be resumed, the day attained greater status for these Jews long before the first pioneers of the Second Aliya settled in Israel. As we acknowledge the ancient roots of the 15th of Shvat - the holiday is not solely a Jewish Arbor Day for Israelis, but a festival rooted in religious faith - there is also no doubt that secular Zionists gave Tu Bishvat new relevance. On that date, a medieval Jew may have eaten fruits from the Land of Israel or may have modified the day's liturgy. Yet, its observance was rooted in an unreal world of esoteric divine redemption. Jews in the Diaspora, before the rise of the Zionist movement, had little intention of actually making aliya to till Israel's soil and consume the fruits of their labor. The Land of Israel was a notion relegated to messianic yearnings. SO MANY of the festivals of the Jewish calendar are rooted in the reality of life in the Land of Israel, yet Jews celebrated them for many centuries knowing full well that they would not be celebrating them in Jerusalem or Tiberias. Israel was a reality only in the sense that at some point at the end of time, God would redeem His people and bring them back to Eretz Yisrael. The 15th of Shvat, for most Jews before the rise of Zionism, was a holiday rooted in an ancient past and in a very distant future. The Zionist movement changed all that. Tu Bishvat has always been a perfect fit for the Zionist movement and its pioneers. Since the beginning of Zionist immigration to the Land of Israel more than a century ago, the New Year of Trees has acquired important significance in the mind, history and mythology of Zionists. The 15th of Shvat is celebrated in Israel today as marking the Jewish revival and redemption of the Land of Israel, the conquest by pioneers of the swampland, as well as the greening of deserts. No longer is the 15th of Shvat a remembrance of things long past or the yearning for an esoteric and faraway future. It is a festival of the here and now, rooted in the historical reality of a people in its homeland. While we should never forget the religious roots of the day and the way Jews celebrated it for centuries, we must also realize that the raising of status of Tu Bishvat from a minor tithing-oriented holiday to a central landmark of Zionism and the State of Israel is a sign that the Jews have reentered the course of history and are living as a free people in the Jewish homeland.