Full moon full moon on 15 Nisan of the Hebrew calendar. The date of the Jewish Rosh Hashana and Sukkot festivals along with all other Jewish holidays are dependent on the dates of the new moons. In lunisolar calendars, an intercalary month occurs seven times in the 19 years of the Metonic cycle, or on average every 2.7 years (19/7). In the Hebrew Calendar this is noted with a periodic extra month of Adar in the early spring. In the modern system of "traditional" full moon names tied to the solstice and equinox points, a supernumerary full moon in such a period
Full moon were less likely. All this is relevant to canine rather than human behavior. Historically, month names are names of moons (lunations, not necessarily full moons) in lunisolar calendars. Since the introduction of the solar Julian calendar in the Roman Empire, and later the Gregorian calendar worldwide, people no longer perceive month names as "moon" names. The traditional Old English month names were equated with the names of the Julian calendar from an early time (soon after Christianization, according to the testimony of Bede ca. AD 700). Some full moons have developed new names in modern times, e.g., the blue moon,