"Tu" (the Hebrew abbreviation of 15th) in the month of Shvat was set (Hillel's opinion generally overrules Shammai's) as the beginning of the tithable year for tree fruit: Calculating the tithe on fruit starts again for fruit that sets after that date.
Here is the quintessential Jewish question: How do we emulate God? We are told that we were created by God. We are told that we have a divine spark within us.
"15th of Shevat;" New Year of the Trees; Jewish Arbor Day, which is a minor festival.
Our role as custodians and stewards of God’s earth is to protect and preserve the ecology and environment as best we can.
In this moment of transition, we will celebrate a different kind of new beginning: Tu BiSh’vat, the new year for trees. Tu BiSh’vat is an opportunity to celebrate the earth and to recommit ourselves, for another year, to environmental action.