One Jewish tradition is celebrated by Hanukkah, which falls in December. It honors the rededication of the Second Temple during the revolt of the Maccabees.
More important than Hanukkah to Jews, is Passover, celebrated in March or April. The Passover is a time for Jews to remember the Exodus, the journey of the Hebrews out of slavery in Egypt.
Ceremonies and rituals are also part of the High Holy Days, the two most sacred of all Jewish holidays. They take place each year in September or October. The first two days of the celebration, Rosh Hashanah, celebrate the beginning of a new year in the Jewish calendar.
On Yom Kippur, which falls soon afterward, Jews ask God to forgive their sins. Jews consider Yom Kippur to be the holiest day of the entire year because it is so holy the Jews don't eat or drink for the entire day.