תָּנוּ רַבָּנַן: מִצְוַת חֲנוּכָּה, נֵר אִישׁ וּבֵיתוֹ. וְהַמְהַדְּרִין, נֵר לְכׇל אֶחָד וְאֶחָד. וְהַמְהַדְּרִין מִן הַמְהַדְּרִין, בֵּית שַׁמַּאי אוֹמְרִים: יוֹם רִאשׁוֹן מַדְלִיק שְׁמֹנָה, מִכָּאן וְאֵילָךְ פּוֹחֵת וְהוֹלֵךְ. וּבֵית הִלֵּל אוֹמְרִים: יוֹם רִאשׁוֹן מַדְלִיק אַחַת, מִכָּאן וְאֵילָךְ מוֹסִיף וְהוֹלֵךְ.
The Sages taught in a baraita: The basic mitzva of Hanukkah is each day to have a light kindled by a person, the head of the household, for himself and his household. And the mehadrin, i.e., those who are meticulous in the performance of mitzvot, kindle a light for each and every one in the household. And the mehadrin min hamehadrin, who are even more meticulous, adjust the number of lights daily. Beit Shammai and Beit Hillel disagree as to the nature of that adjustment. Beit Shammai say: On the first day one kindles eight lights and, from there on, gradually decreases the number of lights until, on the last day of Hanukkah, he kindles one light. And Beit Hillel say: On the first day one kindles one light, and from there on, gradually increases the number of lights until, on the last day, he kindles eight lights.
אָמַר עוּלָּא: פְּלִיגִי בַּהּ תְּרֵי אָמוֹרָאֵי בְּמַעְרְבָא, רַבִּי יוֹסֵי בַּר אָבִין וְרַבִּי יוֹסֵי בַּר זְבִידָא. חַד אָמַר טַעְמָא דְּבֵית שַׁמַּאי כְּנֶגֶד יָמִים הַנִּכְנָסִין, וְטַעְמָא דְּבֵית הִלֵּל כְּנֶגֶד יָמִים הַיּוֹצְאִין. וְחַד אָמַר טַעְמָא דְּבֵית שַׁמַּאי כְּנֶגֶד פָּרֵי הַחַג, וְטַעְמָא דְּבֵית הִלֵּל דְּמַעֲלִין בַּקֹּדֶשׁ וְאֵין מוֹרִידִין.
Ulla said: There were two amora’im in the West, Eretz Yisrael, who disagreed with regard to this dispute, Rabbi Yosei bar Avin and Rabbi Yosei bar Zevida. One said that the reason for Beit Shammai’s opinion is that the number of lights corresponds to the incoming days, i.e., the future. On the first day, eight days remain in Hanukkah, one kindles eight lights, and on the second day seven days remain, one kindles seven, etc. The reason for Beit Hillel’s opinion is that the number of lights corresponds to the outgoing days. Each day, the number of lights corresponds to the number of the days of Hanukkah that were already observed. And one said that the reason for Beit Shammai’s opinion is that the number of lights corresponds to the bulls of the festival of Sukkot: Thirteen were sacrificed on the first day and each succeeding day one fewer was sacrificed (Numbers 29:12–31). The reason for Beit Hillel’s opinion is that the number of lights is based on the principle: One elevates to a higher level in matters of sanctity and one does not downgrade. Therefore, if the objective is to have the number of lights correspond to the number of days, there is no alternative to increasing their number with the passing of each day.
גמ׳ אמר רב חנן בר רבא קלנדא ח' ימים אחר תקופה סטרנורא ח' ימים לפני תקופה וסימנך (תהלים קלט, ה) אחור וקדם צרתני וגו'
GEMARA: Rav Ḥanan bar Rava says: When are these festivals celebrated? Kalenda is celebrated during the eight days after the winter solstice, and Saturnalia is celebrated during the eight days before the winter solstice. And your mnemonic to remember which festival is that the one that occurs after the solstice is mentioned first in the mishna, and the festival that takes place before the solstice is mentioned after, as in the verse: “You have hemmed me in behind and before, and laid Your Hand upon me” (Psalms 139:5), where the word “before” appears after the term “behind.”
ת"ר לפי שראה אדם הראשון יום שמתמעט והולך אמר אוי לי שמא בשביל שסרחתי עולם חשוך בעדי וחוזר לתוהו ובוהו וזו היא מיתה שנקנסה עלי מן השמים עמד וישב ח' ימים בתענית [ובתפלה]
With regard to the dates of these festivals, the Sages taught: When Adam the first man saw that the day was progressively diminishing, as the days become shorter from the autumnal equinox until the winter solstice, he did not yet know that this is a normal phenomenon, and therefore he said: Woe is me; perhaps because I sinned the world is becoming dark around me and will ultimately return to the primordial state of chaos and disorder. And this is the death that was sentenced upon me from Heaven, as it is written: “And to dust shall you return” (Genesis 3:19). He arose and spent eight days in fasting and in prayer.
כיון שראה תקופת טבת וראה יום שמאריך והולך אמר מנהגו של עולם הוא הלך ועשה שמונה ימים טובים לשנה האחרת עשאן לאלו ולאלו ימים טובים הוא קבעם לשם שמים והם קבעום לשם עבודת כוכבים
Once he saw that the season of Tevet, i.e., the winter solstice, had arrived, and saw that the day was progressively lengthening after the solstice, he said: Clearly, the days become shorter and then longer, and this is the order of the world. He went and observed a festival for eight days. Upon the next year, he observed both these eight days on which he had fasted on the previous year, and these eight days of his celebration, as days of festivities. He, Adam, established these festivals for the sake of Heaven, but they, the gentiles of later generations, established them for the sake of idol worship.
Observations
It is interesting to see the machlokes of BS and BH in light of the Gemara in
AZ which indicates the following: In the subsequent year Adam celebrated two sequential holidays; one for the eight days the in which the daylight become
shortest and one in which the eight days begin
to have more daylight
One can see the machlokes BS & BS as an overlay of, or in dialog with the AZ Gemara in one of two ways:
1. That BS & BH are viewing the Chanukah candles as supplementing the daylight in the season of of darkness, BH is focusing on the first eight days in which the daylight gradually lessens. And so he adds one candle per day for eight days to supplement the light. BS is focusing on the second eight days in which daylight gradually increases. He begins with eight candles to supplement the daylight when it is shortest, and decreases the number of candles a the daylight increases.
2. BS and BH are viewing the Chanukah Candles as mimicking the daylight. BS, in Saturnalia, in the first of the eight days the daylight is most and decreases, and BH for in Kalenda the first of the eight days has the least light, and increases.
Either way one can understand and overlay the machlokes BS and BH in terms of the Gemara in AZ.
It is also interesting to think of the Gemara in AZ as appreciating the Yin and Yang nature of the universe. I.e. it is not sufficient to just celebrate the days of increasing daylight, but one needs to do so in conjunction with the decrease in daylight. Adam's days of joy are so, because of his days of consternation.
One "diyuk" in the language of the Gemara in Shabbos 21B. It is understandable that the Gemara describes BS as corresponding to Yamim Ha'nichnasim- the days of Chanukah yet to come. Because we are beginning day one when we light candles, eight full days are yet to come. But it is imprecise to describe BH as corresponding to Yamim Ha'yotzim the days gone by, since when we light candle one no days have gone by. Its would be akin to ascribe making Havdalah on Friday night to mark the end of the Shabbos day, when it is just beginning. Fitting the language Yamim Ha'yotzim the days gone by - would be a practice of lighting the first candle at the end of the first day (like Havdalah) and only lighting for the next seven days. (This actually acknowledges the problem that one day in eight is not a miracle because there was one day's worth of oil.)
Because of this linguistic problem I would suggest that the definition of "Yamim", in Yamim Ha'nichnasim (BS) and Yamim Ha'yotzim (BH) may not relate directly to "days of Chanukah" but rather Yamim in its specific sense of day vs night, of "vayikra Elohim l'Ohr Yom", that the Amorah is defining the position not in terms of Chanukah days, but in terms of days of daylight (like the Gemara in AZ). So for BS Yamim Ha'nichnasim would be the eight days after the solstice; those days when daylight gets gradually greater, so for BS the Chanukah Candles will supplement the sunlight in the day so as daylight increases, the Chanukah lights become fewer. For BH Yamim Ha'yotzim would be the eight days before the solstice; those days when daylight gets gradually less, for for BH the Chanukah candles will supplement the sunlight in the day so as daylight decreases, the Chanukah light become more plentiful.
This play variable between Chanukah and solstice is possible only because Chanukah is based on the lunar calendar and vacillates, occurring before during and after the solstice.
When I learnt these two Gemaros (Shabbos 21B and Avodah Zarah 8A) with Debbie Friedman A"H she, in the subsequent Chanukah, lit two Menorahs, one according to BH and one according to BS. She observed that in doing so each day had the same number of candles because the two opinions in effect supplement each other creating a consistent whole. She saw that in terms of Klal Yisroel, a combining of all our approaches creates our whole.