Chanukah is an eight day holiday which begins on the 25th day of the month of Kislev. It marks the miraculous victory of the Jews, led by the Maccabees, against Greek persecution and religious oppression. In addition to being victorious in war, another miracle occurred: When the Maccabees came to rededicate the Temple, they found only one flask of oil with which to light the Menorah. This small flask lasted for eight days. In order to commemorate this miracle, we light a Menorah for the eight days of Chanukah.
On the evening before each one of the days, the corresponding number of Chanukah candles are lit.