Moon Phases
The Moon moves through eight phases — New Moon, Waxing Crescent, First Quarter, Waxing Gibbous, Full Moon, Waning Gibbous, Last Quarter, and Waning Crescent — over a 29.5-day cycle. This page lists the exact date and time (UTC) of every New Moon, First Quarter, Full Moon, and Last Quarter for each month, along with illumination percentage, moonrise and moonset, and what each phase means for stargazing and tides. Click a moon image below to get more information.
The Moon doesn’t follow the calendar — it follows its own clock, orbiting Earth once every 29.5 days on average (astronomers call this a synodic month). Because that’s neither a neat 28, 30, nor 31 days, the date of each New Moon, Full Moon, and quarter phase creeps forward every month and drifts across the calendar as the year goes on. Below you’ll find a dedicated page for every month, with the exact date and time of each phase and what it means for stargazing, photography, and tides.
Browse by month
Pick a month below for its full phase calendar — exact UTC date and time for each phase, illumination percentage, moonrise and moonset, and what to expect for viewing and tides. Pages go live shortly before the start of each month; check back if the one you’re after isn’t up yet.
How moon phases actually work
The Moon doesn’t produce its own light — everything we see is sunlight bouncing off its surface. As it orbits Earth, the angle between the Sun, the Moon, and us keeps changing, so a different slice of the sunlit half becomes visible each night. At New Moon, the Moon sits between us and the Sun, so the lit half faces entirely away and the Moon appears dark. Two weeks later, at Full Moon, the Moon is on the opposite side of Earth from the Sun, so we see the entire lit half at once.
Between those two extremes, the visible sliver grows (“waxes”) for about two weeks, then shrinks (“wanes”) for about two more, passing through First Quarter and Last Quarter along the way, when exactly half the face is lit. That full waxing-to-waning cycle is what each monthly page on this site tracks.
Why the dates shift every year
A calendar year runs about 365.25 days. Twelve lunar cycles run about 354 days — roughly 11 days shorter. That gap is why, say, this year’s first Full Moon of January might fall on the 3rd, but next January’s falls around the 23rd, and the year after that lands back near the start again. Left unchecked, this drift would eventually cycle a given phase through every date on the calendar and back — it takes about 19 years (the Metonic cycle) for the Moon’s phases to realign with the same calendar dates.
That’s also why some months contain two of the same major phase — most often two Full Moons, sometimes called a Blue Moon — while others skip a phase entirely.
Moon phases and tides
Tides are driven mainly by the Moon’s gravity pulling on Earth’s oceans, with the Sun adding a smaller pull of its own. Around New Moon and Full Moon, the Sun, Earth, and Moon line up, so the two pulls combine — this produces spring tides, where high tides are higher and low tides are lower than average. Around the quarter phases, the Sun and Moon are pulling at roughly right angles to each other, partly cancelling out. That produces neap tides, with a smaller gap between high and low water. If you’re planning anything tide-dependent — fishing, boating, beachcombing — the phase calendar on each monthly page doubles as a rough tide-range guide.
Best phases for stargazing and photography
For stargazing, New Moon is the best window: with no moonlight in the sky, faint stars, planets, and the Milky Way show up far more clearly. As the Moon waxes past First Quarter, its brightness starts washing out dimmer objects, and by Full Moon it can drown out all but the brightest stars.
For photographing the Moon itself, the extremes are less interesting than the phases in between. Around First and Last Quarter, sunlight hits the surface at a low angle along the line dividing light from shadow (the terminator), throwing long shadows off craters and mountains and making the surface look far more three-dimensional than the flat, fully-lit look of a Full Moon.
Frequently asked questions
What time zone are the listed times in?
All dates and times on this site are given in UTC. Convert to your local time zone to know exactly when a phase occurs where you are — the date can shift by a day depending on your offset from UTC.
How accurate are the dates and times listed?
Dates and times are calculated from lunar orbital data and are accurate to within a couple of minutes.
What’s a Blue Moon?
Most commonly, it’s the name for a second Full Moon occurring within the same calendar month — a result of the 29.5-day lunar cycle occasionally fitting twice into a 30- or 31-day month. It has nothing to do with the Moon’s actual color.
What’s the difference between a Full Moon and a Supermoon?
“Supermoon” isn’t an official phase — it’s a Full Moon (or New Moon) that happens to coincide with perigee, the point in the Moon’s orbit where it’s closest to Earth. Because the orbit is slightly elliptical, distance varies by about 12–13% over a cycle, so a supermoon can look up to 14% larger and 30% brighter than a Full Moon at its farthest point (apogee).
How is the illumination percentage calculated?
It’s the fraction of the Moon’s visible disc that’s lit by the Sun, based on the Sun-Earth-Moon angle at that exact moment. 0% is New Moon, 100% is Full Moon, and roughly 50% marks First and Last Quarter — though because the Moon keeps moving, illumination is really a snapshot rather than a fixed number for the whole day.
Do moon phases look the same everywhere on Earth?
The phase itself (how much is lit) is the same worldwide at a given moment, but orientation isn’t. In the Southern Hemisphere, a waxing crescent appears to curve the opposite way it does in the Northern Hemisphere, since observers there are effectively looking at the Moon “upside down” relative to a Northern Hemisphere view.
Do moon phases cause eclipses?
Eclipses can only happen at specific phases: lunar eclipses occur at Full Moon, when Earth passes between the Sun and Moon, and solar eclipses occur at New Moon, when the Moon passes between the Sun and Earth. They don’t happen every single New or Full Moon, though, because the Moon’s orbit is tilted slightly relative to Earth’s — alignment has to be close to exact.
Is there a quick way to estimate moonrise and moonset by phase?
Roughly: New Moon rises and sets with the Sun, First Quarter rises around midday and sets around midnight, Full Moon rises around sunset and sets around sunrise, and Last Quarter rises around midnight and sets around midday.
For daily high-resolution renderings of the Moon’s phase and orientation, see NASA’s Scientific Visualization Studio.
View NASA’s Moon Phase Gallery