Shevat is the eleventh month of the biblical calendar year. "Shevat" is the Babylonian name of the month. In the Bible, it is referred to as both "the eleventh month" and "Shevat" (or Shebat), as in Zechariah 1:7, "On the twenty-fourth day of the eleventh month, which is the month of Shebat, in the second year of Darius, the word of the LORD came to the prophet Zechariah..."
The month of Shevat contains a minor festival on 15 Shevat known as Tu B'Shevat. This day is one of four days considered to be a Rosh Hashanah (New Year) on the biblical calendar. It is on this day that Israel commemorates the new year for trees and produce, in regards to tithing produce and the counting of the age for trees.
Trees and produce are some of the foremost reasons the land of Israel is praised so highly. In Deuteronomy 8, the land is spoken of as,
A good land, a land of brooks of water, of fountains and springs, flowing out in the valleys and hills, and land of wheat and barley, of vines and fig trees and pomegranates, a land of olive trees and honey, and land in which you will eat bread without scarcity, in which you will lack nothing...And you shall eat and be full, and you shall bless the LORD your God for the good land he has given you. (8:7-10)
It is customary to eat fruit grown in the land of Israel on this special day. In Israel today, it is a day of celebration for the religious and secular alike. For when the land is renewed from the precipitation, it can once again bring forth its bountiful growth. Thus, its renewal is an occasion for great rejoicing and thanksgiving to God who provides us with good and nourishing sustenance.
Chag Sameach from First Fruits of Zion!