Time & date
Moon Phase Today
Today’s moon phase, how much of the Moon is lit, and when the next new, quarter and full moons happen, in your own time zone.
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Frequently asked questions
How accurate are the moon phase times?
The phases are calculated with Jean Meeus’s algorithms from Astronomical Algorithms, the standard reference for this kind of calculation. Checked against the US Naval Observatory’s published phases for eleven sample years between 1901 and 2050, all 542 new, quarter and full moon times matched to within a minute. Moonrise and moonset times for London, New York, Sydney, Tokyo, Reykjavik and Singapore matched the USNO to within a minute as well.
What do the phase names mean?
New moon, first quarter, full moon and last quarter are exact moments, when the Moon is 0°, 90°, 180° and 270° east of the Sun. Following the almanac convention, the whole calendar day on which one of those moments falls carries its name. The days between are named from the Moon’s shape: crescent when less than half the disc is lit, gibbous when more than half is lit, waxing while the lit part grows and waning while it shrinks.
Why is a “quarter” moon half lit?
The name refers to the Moon’s journey, not its shape. At first quarter the Moon has completed a quarter of its orbit since new moon, and at that point we see half of the disc lit. At last quarter it is three quarters of the way round, and again half of the disc is lit, but the other half.
What is the moon age?
It is the time since the most recent new moon, in days. A full cycle of phases, the synodic month, averages 29.53 days, but a single cycle can be six to seven hours shorter or longer because the Moon’s orbit is elliptical. For the same reason, full moon falls when the Moon is anywhere from about 13.9 to 15.6 days old.
Why does the Moon look different in the Southern Hemisphere?
Observers south of the equator see the Moon upside down compared with those in the north, so a waxing crescent is lit on the left instead of the right. The phase and its timing are the same everywhere on Earth at the same instant. The page picks the view from your city’s latitude, and the North and South view buttons let you switch. Near the equator the crescent lies closer to horizontal, like a boat.
Where do names like Wolf Moon and Harvest Moon come from?
They are folk names, popularised by the Old Farmer’s Almanac and drawn from Native American, Colonial American and European traditions, and they are tied to the seasons of the Northern Hemisphere. Astronomy has no official names for full moons. The Harvest Moon is the full moon closest to the September equinox, so it can fall in October, and the Hunter’s Moon is the one after it. A Blue Moon is used here for the second full moon in a calendar month.
About this tool
This moon phase calculator shows what the Moon looks like today, how much of it is lit, and exactly when the next new moon, first quarter, full moon and last quarter will happen. The times are shown in your own time zone, including daylight saving time, so a full moon at 16:49 UTC appears as 17:49 in London in summer or 12:49 in New York. You can look up any date from 1900 to 2100, useful for finding the moon phase on a birthday or planning an evening under a dark sky.
Everything is calculated in your browser. The principal phases come from the series in chapter 49 of Jean Meeus’s Astronomical Algorithms, and the percentage lit and waxing or waning state come from the Moon and Sun positions in chapters 47 and 25, adjusted for the small difference between atomic time and Earth rotation time. The results were checked against the US Naval Observatory: phase times agree to within a minute, and the percentage lit agrees to within the USNO’s rounding.
The monthly moon calendar draws each day’s Moon from its actual percentage lit, so you can see the crescent thicken towards full moon and thin again towards new moon. Days with a principal phase are highlighted and show the exact time. Because the Moon appears upside down south of the equator, the drawings follow your hemisphere, and you can switch between the northern and southern view.
Choosing a city also gives the day’s moonrise and moonset, calculated for the Moon’s upper edge on a flat horizon with standard atmospheric refraction, the same definition the USNO uses. The Moon rises about 50 minutes later each day on average, so some dates have no moonrise or no moonset at all. The list of the year’s full moons adds their traditional names, from the Wolf Moon in January to the Cold Moon in December, along with the Harvest Moon and any Blue Moon.