Why does the miracle of Hanukkah last eight days?

Question: Is there additional meaning in the fact that Hanukkah falls at the end of the month of Kislev and lasts eight days?

Answer:

The Ben Ish Chai explains that the timing of the holiday hints at the cancellation of the Greek decrees.

Since Hanukkah begins on the 25th of Kislev and lasts eight days, the days of the holiday include a Shabbat and usually also Rosh Chodesh Tevet, and so they recall two of the mitzvot that the Greeks tried to abolish.

The third mitzvah, brit milah, is connected to the eighth day.

In this way the eight days of Hanukkah can be seen as a reminder of the spiritual victory of the Jewish people and of their faithfulness to the mitzvot.