I am familiar with a Passover seder, but what is a Tu BiShvat seder?
Tu BiShvat (Hebrew for the 15th day of the Hebrew month of Shvat) is the new year of the trees.
Why is the Jewish Sabbath observed on Saturday?
Genesis, Chapter 1 provides the basis for the Jewish week and the understanding of its days.
Celebrate Tu Bishvat with Shalom Sesame: Honoring the Trees
Celebrate Tu Bishvat with Shalom Sesame: Tikkun Olam
Shabbat Shirah
Aromatic Clementine Lanterns - Bundles of Bounty and Beauty
aliyah
"Going up." The honor of being called to recite the blessings before and after the Torah reading. Also refers to immigration to Israel, to "make aliyah" to Israel; plural: aliyot. Lit. "Ascent."
challah
A braided egg bread eaten on Shabbat and festivals. Today challah comes in many flavors and varieties, including chocolate chip, gluten free, and vegan. Plural: challot.
havdalah
Literally, “separation." The Saturday night home ritual that separates the Sabbath from the beginning of the new week. The ritual uses wine, spices, and candles to transition from Sabbath to the weekdays.
Kiddush
"Sanctification;" blessing recited or chanted over wine (or grape juice), emphasizing the holiness of Shabbat and festivals.