§ The mishna continues: And one sounds no more than forty-eight trumpet blasts on any given day. The Gemara wonders: And are there no more than forty-eight on any day? But isn’t there Passover eve that occurs on Shabbat, where if it is according to Rabbi Yehuda, there would be fifty-one blasts, i.e., twenty-one daily blasts, nine for the additional offering of Shabbat, nine for the hallel of each of the first two shifts sacrificing the Paschal lamb, and three for the third shift; and if it is according to the Rabbis, who hold that nine blasts were sounded for the third shift as well, there would be fifty-seven blasts? According to both opinions, there are more than forty-eight. The Gemara answers: When the tanna teaches the mishna, he is teaching matters that occur every year; the case of Passover eve that occurs on Shabbat, which is a matter that does not occur each and every year, he does not teach. The Gemara asks: Is that to say that Shabbat eve during the Festival occurs every year? There are times when you do not find a Friday during the intermediate days of Sukkot. And what are the circumstances? It is a case where the first Festival day occurs on Shabbat eve, and therefore the following Friday is the Eighth Day of Assembly. The Gemara answers: That cannot be, as when the first Festival day of Sukkot would happen to occur on Shabbat eve, we postpone it by adding a day to the month of Elul and observing both Rosh HaShana and the first day of Sukkot on Shabbat. What is the reason for doing so? The reason is: Since if the first Festival day occurs on Shabbat eve, when is Yom Kippur that year? It is on Sunday. Therefore, in order to avoid two consecutive days, Shabbat and Yom Kippur, when there is a severe prohibition against performing labor, we postpone Rosh HaShana. The first Festival day never coincides with Friday. The Gemara asks: And do we postpone it to prevent Yom Kippur from occurring on Sunday? But didn’t we learn in a mishna: The fats of the offerings slaughtered and sacrificed on Shabbat that were not yet burned on the altar may be sacrificed on Yom Kippur that begins at the conclusion of Shabbat? And Rabbi Zeira said: When we were studying in the school of Rav in Babylonia, they said with regard to that which was taught in the baraita: On Yom Kippur that occurs on Shabbat eve they did not sound the trumpets to stop the people from their labor and signify the onset of Shabbat, and if it occurred at the conclusion of Shabbat they would not recite havdala after Shabbat, that it is undisputed, as everyone agrees to that halakha. However, when I ascended to there, to Eretz Yisrael, I found Rabbi Yehuda, son of Rabbi Shimon ben Pazi, who was sitting and saying that this is the opinion of Rabbi Akiva, and the other Sages disagree. From both of these sources, it is apparent that Yom Kippur can occur both before and after Shabbat. The question remains: Why did the tanna cite a case that does not occur every year? The Gemara answers: This is not difficult. This, the mishna, from which it is understood that there will always be a Friday during the Festival, is in accordance with the opinion of the Rabbis, who maintain that Rosh HaShana is postponed to ensure that Yom Kippur will not occur adjacent to Shabbat. However, this mishna, which teaches that the fats of Shabbat may be sacrificed at the conclusion of Shabbat on Yom Kippur, and Rosh HaShana is not postponed, is in accordance with the opinion of Aḥerim, who maintain that there are a fixed number of days in a year and a fixed number of days in a month. As it is taught in a baraita: Aḥerim say: Between the festival of Shavuot one year and the festival of Shavuot the following year, and similarly, between Rosh HaShana one year and Rosh HaShana the following year, there is a difference of only four days of the week. And if it was a leap year there is a difference of five days between them. The 354 days in the year are divided among twelve months; six months are thirty days long and six months are twenty-nine days long. Since according to Aḥerim the number of days is constant, Rosh HaShana could occur on any day of the week.