The festival of Rosh Hashanah—the name means “Head of the Year”—is observed for two days beginning on 1 Tishrei, the first day of the Jewish year.
Yom Kippur is the holiest day of the year—the day on which we are closest to G‑d and to the quintessence of our own souls. It is the Day of Atonement.
For forty years, as our ancestors traversed the Sinai Desert, following the Exodus from Egypt, miraculous "clouds of glory" surrounded and hovered over them. Atonement.
The holiday of Sukkot is followed by an independent holiday called Shemini Atzeret and Simchat Torah. Atonement.
Chanukah -- the eight-day festival of light celebrates the triumph of light over darkness, of purity over adulteration, of spirituality over materiality. Atonement.
The festival of Purim is celebrated every year on the 14th of the Hebrew month of Adar (late winter/early spring). Atonement.
The eight-day festival of Passover is celebrated in the early spring, from the 15th through the 22nd of the Hebrew month of Nissan. It commemorates the emancipation of the Israelites from slavery in ancient Egypt. Atonement.
The Torah was given by G‑d to the Jewish people on Mount Sinai more than 3300 years ago. Every year on the holiday of Shavuot we renew our acceptance of G‑d’s gift, and G‑d “re-gives” the Torah. Atonement.