One textual basis for Tu BiShvat has been found in Leviticus 19:23–25, where God instructs Moses that the fruit of trees in Israel shall be unholy for three years, offered to God in the fourth year, and allowed to be eaten only in the fifth year. The writers of the Talmud established Tu BiShvat as the birthday of all trees for ritual purposes, one of four new years in the Jewish religious calendar.