Yom Kippur (observed) - No school

Yom Kippur is one of the two High Holy Days, or Days of Awe (Hebrew yamim noraim), alongside Rosh Hashana (which falls 9 days previously).[10] According to Jewish tradition, on Rosh Hashanah God inscribes each person's fate for the coming year into the Book of Life, and waits until Yom Kippur to "seal" the verdict.[11] This process is described dramatically in the poem Unetanneh Tokef, which is recited on Rosh Hashanah and Yom Kippur.

Information taken from Wikipedia