The Hebrew calendar is a lunisolar calendar, meaning that it is based on both the lunar cycle and the solar cycle. The months of the Hebrew calendar are Elul (אלול) and ADAR (עֲדַר). Elul is the twelfth month of the Hebrew calendar and is usually 30 days long. It is a time of preparation for the High Holidays of Rosh Hashanah and Yom Kippur. ADAR is the sixth month of the Hebrew calendar and is usually 29 days long. It is a time of celebration and joy, as it marks the beginning of the Jewish holiday of Purim.