Full moon the first full moon of 2000. The true time of a full moon may differ from this approximation by up to about 14.5 hours as a result of the non-circularity of the moon's orbit. See New moon for an explanation of the formula and its parameters. The age and apparent size of the full moon vary in a cycle of just under 14 synodic months, which has been referred to as a full moon cycle. Full moons are traditionally associated with temporal insomnia (inability to sleep), insanity (hence the terms "lunacy" and "lunatic") and various "magical phenomena" such as lycanthropy.
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,