Lunar Calendar

Choose the range or month you want to inspect. Phase labels tell you how much of the Moon's near side is sunlit from Earth's viewpoint. Full moon occurs when Earth is roughly between Sun and Moon; new moon when the Moon is between Earth and Sun (modulo tilt).

The synodic month—new moon to new moon—is about 29.5 days, which is why lunar calendars insert leap months or shift festival dates relative to purely solar calendars. The Moon also drifts perigee and apogee, changing apparent size slightly (supermoon hype vs ordinary full moons).

Popularly, the second full moon in a single calendar month. The phrase has older almanac meanings too; headlines usually mean the monthly double-full-moon sense.

Phases indicate geometry, but local tide charts depend on coastline shape, weather, and the sun's pull too. Use marine tide tables—not this calendar—for boating clearance.

• Night photography: Plan shoots when moonlight matches the mood you want.
• Outdoor events: Expect brighter skies near full moon for stargazing parties—or more darkness near new moon.
• Cultural planning: Roughly align potlucks or traditions that reference moon cycles with visible phase windows.