Orbit of the Moon orbit of the Moon is distinctly elliptical, with an average eccentricity of 0.0549. The non-circular form of the lunar orbit causes variations in the Moon's angular speed and apparent size as it moves towards and away from an observer on Earth. The mean angular movement relative to an imaginary observer at the Earth-Moon barycentre is ° per day to the east (Julian day 2000). The Moon's elongation is its angular distance east of the Sun at any time. At new moon, it is zero and the Moon is said to be in conjunction. At full moon, the elongation is 180°
Tishri-years the years from the Autumn season, around the Autumn Equinox (Gregorian September 22/23). The New Years Day of the Tishri-years is called "Rosh Hashanah" ("Head of the Year"); it begins the Fall Feasts of Israel. Tishri 1, however, is not determined directly by its relationship to the Autumn Equinox. It depends on the determination of Nisan 1, which is the day after the New Moon closest to the Spring Equinox (within fifteen days before or after). Tishri 1 is the first day of the seventh month. Although the month number is always counted from Nisan, in the Tishri-years, the year