Hanukkah, also known as Chanukah and the Festival of Lights, is celebrated from December 13, 2017 till December 20, 2017. The Jewish holiday commemores the rededication of the Holy Temple in Jerusalem at the time of the Maccabean Revolt of the 2nd century BCE. Hanukkah is observed for eight nights and days, starting on the 25th day of Kislev according to the Hebrew calendar.
Hanukkah is celebrated by a series of rituals that are performed every day throughout the 8-day holiday, some are family-based and others communal. There are special additions to the daily prayer service, and a section is added to the blessing after meals. Hanukkah is not a "Sabbath-like" holiday, and there is no obligation to refrain from activities that are forbidden on the Sabbath. Adherents go to work as usual, but may leave early in order to be home to kindle the lights at nightfall. Many families exchange small gifts each night, such as books or games. Fried foods are eaten to commemorate the importance of oil during the celebration of Hanukkah.
The festival is observed by the kindling of the lights of a unique candelabrum, the nine-branched Menorah or Hanukiah, one additional light on each night of the holiday, progressing to eight on the final night. The typical Menorah consists of eight branches with an additional raised branch. The extra light is called a shamash and is given a distinct location, usually above or below the rest. The purpose of the shamash is to have a light available for use, as using the Hanukkah lights themselves is forbidden. (With material from: Wikipedia)