What is Hanukkah and when is it celebrate?

Answer 1

Hanukkah starts on the Hebrew calendar date of 25 Kislev, and lasts for eight days. Here are the coinciding secular dates for the upcoming years:
2013: November 27-December 5
2014: December 16-24
2015: December 6-14

Hanukkah commemorates the Maccabean War of 165 BCE, between the Jews and the Syrian-Greeks. The real miracle of Hanukkah is that the Jews were victorious, against all odds, they beat their enemy and were able to restore the ancient Temple in Jerusalem, which had been desecrated by the Greeks. In a larger context, Hanukkah represents victory against religious persecution and assimilation.
But a second miracle is more commonly known: A story in the Talmud (500 years later) tells of a legendary miracle. After the war, When the Jews returned to rededicate the ancient Temple, they found that there was only enough oil to keep the eternal lamp burning for 1 day. It would take 8 days to make more of this special oil. So the lit the lamp, and it miraculously burned for 8 days, giving them plenty of time to make more oil to keep the lamp burning.
This second miracle is very popular with children. It is understood as a legend only, and appears to be the early Rabbis' attempt to add a spiritual level to the holiday.

Answer:The above answer is non-traditional. The tradition of religious Judaism is that the miracle described above did indeed occur and is not a mere legend.
On Hanukkah, the chief celebration is for the miracle of the oil (Talmud, Shabbat 21b), which occurred during the Hasmonean victory over the Syrian-Greeks; and we also thank God for His having helped us to oust the Syrian-Greeks (Seleucids) and their lackeys, the Hellenizing Jews. The Seleucids, at the instigation of the Hellenizers, had forbidden various Torah-practices, such as Sabbath-observance, and pressed the Jews to offer up idolatrous sacrifices. The Hasmoneans (a religious Jewish family) fought to retake the Holy Temple, which had been seized by the Seleucids, and to enable the people to once again observe the Torah. When they reached the Temple grounds, they found only one day's supply of unsullied olive oil, but the oil lamps miraculously burned for eight days (ibid.), allowing enough time for new oil to be prepared and brought.
The significance of the miracle is that it demonstrated that God's presence still dwelt in the Holy Temple.
The Al-Hanisim prayer recited during Hanukkah centers around the Hasmoneans' victory, while the candle-lighting commemorates the miracle of the oil.
Though the military victory is prominently mentioned in the prayers, it wouldn't have been celebrated if not for the miracle of the oil, just as we have no special occasion to mark Abraham's victory (Genesis ch.14), or those of Moses (Numbers ch.21), Joshua, Deborah (Judges ch.4), Gideon (Judges ch.6-7), Jephthah (Judges ch.11), or King David. And though the Hasmonean battles continued for two decades after the retaking of the Temple, the Sages instituted Hanukkah immediately after the miracle of the oil.
It should also be noted that the main goal for which the Maccabees fought was not political independence. They fought to enable the people to observe the Torah's commandments; as we say in the Al Hanisim prayer: "the Greeks sought to cause us to forget Your Torah and leave Your statutes."