Tu BiShvat (Hebrew for the 15th day of the Hebrew month of Shvat) is the new year of the trees.
The blessing after the reading of haftarah always sanctifies the day on which it is read. Throughout most of the year, that day is Shabbat, but haftarahis also read on the High Holidays. On Rosh HaShanah and Yom Kippur the text changes from the familiar Shabbat text to refer to the holiday.
Normally, two loaves of elongated challah are served for Shabbat, but for the High Holidays a round challah, sometimes containing raisins, is customary.