In Judaism, the High Holy Days, also known as High Holidays or Days of Awe consist of:strictly, the holidays of Rosh Hashanah and Yom Kippur ; by extension, the period of ten days including those holidays, known also as the Ten Days of Repentance ; or, by a further extension, the entire 40-day penitential period in the Jewish year from Rosh Chodesh Elul to Yom Kippur, traditionally taken to represent the forty days Moses spent on Mount Sinai before coming down with the second ("replacement") set of the Tablets of Stone.

Elul is the twelfth month of the civil year and the sixth month of the religious year in the Hebrew calendar. It is a month of 29 days. Elul usually occurs in August–September on the Gregorian calendar.