The Beginning of “Tekufat Nissan” as the Epoch of the Jewish Calendar and the Correspondence between “Molad VAYAD” and the Almagest

Abstract

"Molad Adam" is regarded as the basic New moon of the permanent Jewish calendar because it takes place on a Friday at exactly the hour of 8 AM or exactly 14 hours after the beginning of the day according to the Jewish calendar, even though "Molad Tohu" is the New moon which starts the first year of the calendar 12 months earlier.
In the Jewish tradition, the dispute between Rabbi Yehoshua and Rabbi Eliezer is known as the question of when the world was created – in Nissan or Tishrei. Therefore, the choice of the "Molad Adam" as a new moon that takes place in a rounded hour and thus making it practical to begin the calculation of the dates of all new moons of the Hebrew calendar (in addition to the choice of "Molad Tohu" as the first new moon of the calendar), indicates the victory of the approach that the creation of the world was in Tishrei. As a consequence, it can be stated that the epoch of the Jewish calendar is adjacent to the beginning of Tekufat Tishrei and not to the beginning of Tekufat Nissan.
In this paper, we will demonstrate that the determination of the time at which "Molad Adam" took place based on the corresponding new moon of the almagest leads to the fact that when the first new moon of Tekufat Tishrei is the epoch of the calendar and based on the value of the “equation of time” at this epoch, the day time of the new moon will take place at the exact hour of 8 am Jerusalem time.