On the 25th of Kislev in the year 3622 from creation, the Maccabees liberated the Holy Temple in Jerusalem, after defeating the vastly more numerous and powerful armies of the Syrian-Greek king Antiochus IV, who had tried to forcefully uproot the beliefs and practices of Judaism from the people of Israel. The victorious Jews repaired, cleansed and rededicated the Temple to the service of G-d. But all the Temple's oil had been defiled by the pagan invaders; when the Jews sought to light the Temple's menorah (candelabra), they found only one small cruse of ritually pure olive oil. Miraculously, the one-day supply burned for eight days, until new, pure oil could be obtained. In commemoration, the Sages instituted the 8-day festival of Chanukah, on which lights are kindled nightly to recall and publicize the miracle.
Link: The Story of Chanukah
The eighth day of Chanukah is also known as Zot Chanukah (lit., "this is Chanukah"), after a key phrase in the special Chanukah Torah reading for this day (Numbers 7:54-8:4).
In the Jewish calendar, the day begins at nightfall; thus, the last kindling of the Chanukah lights is held on the evening preceding the 8th day of Chanukah, when eight lights are lit (see "Laws & Customs" for yesterday's date). The festival of Chanukah concludes at nightfall this evening.
It is customary, however, to light candles during the daytime as well, in synagogues, in public spaces, and at gatherings held in honor of the festival. These lightings are done without recitation of the blessings as they do not constitute an observance of the mitzvah of kindling the Chanukah lights.
Link: What Is Zot Chanukah?
Without miracles, we might come to believe that the laws of physics define reality. Once we witness the inexplicable, we see that it’s not a closed system, that there is a higher reality.
And then we look back at physics and say, “This too is a miracle.”
The miracle of a small flask of oil burning for eight days was this sort of miracle. The combustion of oil and oxygen generated light, and yet the quantity of oil did not diminish.
Then there are those small miracles that occur every day, those acts of synchronicity we call “coincidence,” because in them G‑d prefers to remain incognito, leaving all the laws of nature intact.
Indeed, that is an even greater miracle, that G‑d can achieve whatever He so desires non-invasively, as though He weren’t even there.
These were the sort of miracles the tiny band of Maccabees saw in their battles against the mighty Greek army. They fought bravely, but in their hearts they knew a great miracle happened here.
So too, when we open our eyes and hearts, we ponder those everyday coincidences and we awaken to the realization that there is truly no place void of this wondrous, unlimited G‑d.