הלכה על שמות 34:22

It is from the roots of this commandment [that it is] so that Israel shall make God's holidays in their (proper) times, as God commanded that we make Pesach in the time that the produce is in [bloom], as it is written (Deuteronomy 16:1), "Observe the month of Spring, and you shall offer the Pesach sacrifice." And the holiday of Sukkot is [to fall] at the time of the harvest, as is written, "And the holiday of the harvest at the turn of the year." (Exodus 34:22) And were it not for intercalation, the holidays would come not at these times, since Israel calculates their months and festivals according to the lunar year, which has three hundred and fifty-four days, eight hours, and eight hundred and seventy-six parts, which is less than the solar year by ten days, twenty-one hours and two hundred and four parts - its mnemonic is ten, twenty-one, two hundred and four. Due to the ripening of the produce and fruit from the power of the sun, it turns out that but for intercalation - by which we align the lunar and solar years - Pesach would not come in the Spring, nor Sukkot at the time of the harvest. And this matter is to be fixed by the greatest [sages] of the generation, since it is a matter requiring great wisdom. And since it is also said that from this [calculation, one comes to know] the agricultural happenings of the year, it is appropriate to give [this task] only to great and pious men.

Therefore, natural philosophers said that by right the year should begin with the point of intersection (equinoctial point) from which the sun begins to approach the inhabited portion of the earth (the northern hemisphere).⁷³ This is a “tropical year,” the period from one vernal equinox until the following vernal equinox. This is the cycle of Rav Adda.⁷⁴ Rav Adda’s year is a tropical year. Although his cycle is based on the average orbit, its correction is simple.⁷⁵ Rav Adda’s figure is for a mean solar year. Corrections need to be made to accommodate apparent variations in the solar orbit. This was also the beginning of the year for those who developed the Hebrew calendar. This was also the beginning of the year for the early Greeks.⁷⁶ See Evans, pp. 182–184 for a discussion of early Greek calendars. This is the vernal equinox. The Persians begin their year with the summer solstice, the Chaldeans with the autumnal equinox, and the Christians with the winter solstice. However the Christians are in error since their calculation of the solar year is not correct.⁷⁷ During the lifetime of Ibn Ezra, Christians followed the Julian calendar, with a year consisting of exactly 365¼ days. In the year 1582 the Church reformed its calendar and adopted the Gregorian version, improving upon the approximation of the Julian calendar.

We also find written⁸³ Ibn Ezra now proceeds to show that for some matters the year begins with the month of Tishre. Here he seems to be countering the Karites, who did not accept the first of Tishre as Rosh haShana. The Karites argued that there is no Scriptural basis for the first of Tishre being anything other than a day when work is forbidden (Leviticus 23:23–25) and special sacrifices are offered (Numbers 29: 1–5). The Karites began the year for all religious matters with the first of Nisan. with regard to Tabernacles “at the turn of the year” (Exodus 34:22), and also “at the departure of the year” (ibid. 23:16). Now the same day when one year ends a new year begins. We also find that God instructed us in a law of Haqhel, when the entire Torah is read during the holiday of Tabernacles of a Sabbatical year (Deuteronomy 31:10–13). There it is written “in order that they may learn” (ibid. 31:12). It is not likely that this took place after half a year.⁸⁴ Thus, Haqhel certainly took place at the beginning of a Sabbatical year, indicating that a Sabbatical year began around the time of Tabernacles. Do not be perplexed by the word “At an end (miqqez) of seven years” (ibid. 31:10),⁸⁵ The verse concerning Haqhel reads: “At the end of seven years, in the time of the Sabbatical year, on the holiday of Tabernacles,” which seems to indicate that the celebration of Haqhel took place at the conclusion of the Sabbatical year and the beginning of the eighth year. for we similarly find “At an end (miqqez) of seven years you shall send forth, each man his brother” (Jeremiah 34:14).⁸⁶ We know that servants were set free after six years (Exodus 21:2). Thus “miqqez” must here refer to the beginning of the seventh year. Similarly for Haqhel, the word “miqqez” means “beginning” rather than “end.” For each thing has two edges, a front edge and a back edge. The Sabbatical year began with Tishre,⁸⁷ Here Ibn Ezra refutes the Karites who began the Sabbatical year with Nisan. (See Ibn Ezra’s commentary to Leviticus 25:20.) which is the seventh month, since then the half year of planting began. Thus it states regarding the Sabbatical year “do not plant” (Leviticus 25:4), and “You shall plant on the eighth year” (ibid. 25:22).