קביעוּת ודחיוֹת שׁל ראשׁ השׁנה A Modern Commentary to Maimonides, Chapter 7 הלכות קידוש החודש

תקציר

<p><span>Rosh Hashanah is set on the day of the Molad, subject to four postponements: 1. Lo ADU Rosh; Rosh Hashanah cannot fall on Sunday, Wednesday, Friday. 2. Molad Zaken; If Molad falls after noon (18 hours). The next two postponements are derivative and relate to the allowable year length of 353-355 days for a common year, and 383-385 days for a leap year. 3. GATRAD common year. This postponement is to prevent a common year from exceeding 355 days. It postpones Rosh Hashanah to Thursday when Molad is Tuesday, 9 hours in the night, 204 halakim or later. The next Rosh Hashanah’s Molad will fall on Saturday 18 hours (molad zaken) or later, causing a postponement to Monday. If the current year Rosh Hashanah is allowed to fall on Tuesday and the next on Monday, the year will be 356 days long. 4. BATU TATPAT after a leap year. This postponement is to prevent the preceding leap year from being less than 383 days. It postpones Rosh Hashanah to Tuesday when Molad is Monday, 15 hours, 589 halakim, or later. The previous Rosh Hashanah was a Tuesday Molad Zaken, causing a postponement to Thursday. If the current year Rosh Hashanah is allowed to fall on Monday, the previous year will have been 382 days. Rambam’s general reason <span>דחיות</span><span></span><span></span><span></span><span></span> differs from the classical reasons provided by Talmud for Adu. According to Rambam, it is to allow Rosh Hashanah to fall closer to the true astronomical Molad, and perhaps also to the day of first visibility. Around Rosh Hashanah, visibility is at its most delayed relative to the other months of year. Hebrew abstract in document.</span><span></span></p>