How to read the calendar
Each cell shows the Moon as it looks at 12:00 Universal Time on that day, with the percentage of the disc that is lit. The four principal phases are written in the cell of the day they fall on, and the list under each month gives their time to the minute. Open a month to see a larger grid, the name of the full moon and the nights that are best for the stars.
All times start in Universal Time and are converted to the time zone of your device as soon as the page loads. A note under the calendar tells you which time zone is used.
Why the phases shift every year
The Moon returns to the same phase every 29.53 days. Twelve of these lunations add up to 354 days. The phases therefore come about eleven days earlier each year: a full moon on 24 November 2026 is followed, a year later, by one on 14 November 2027. After nineteen years the pattern nearly repeats, because 235 lunations last almost exactly nineteen years. That cycle, named after the Greek astronomer Meton, is the basis of the Hebrew calendar and of the calculation of the date of Easter.
What people use a lunar calendar for
- Stargazing and astrophotography. The week around the new moon gives the darkest sky. A full moon washes out the Milky Way and all but the brightest meteors.
- Night photography and hiking. The days around the full moon give enough light to walk without a lamp, and a Moon that rises near sunset.
- Fishing and tides. The strongest tides, called spring tides, follow the new moon and the full moon by a day or two. The weakest follow the quarters.
- Gardening by the Moon. Many gardeners sow and prune by the phase. Controlled trials have not found an effect on growth, but the calendar gives the dates either way.
- Religious calendars. The months of the Islamic calendar begin with the first sighting of the thin crescent, one or two evenings after the new moon. Hebrew, Chinese and Hindu calendars also follow the lunations.
Questions and answers
How many full moons are there in a year?
Twelve in most years, thirteen in some. Twelve lunations last 354 days, eleven days short of a calendar year, so about every two and a half years a thirteenth full moon fits in. When two full moons fall in the same calendar month, the second is often called a blue moon.
Why does another calendar show the full moon on a different day?
A phase happens at one instant for the whole planet, but the date at that instant depends on your time zone. A full moon at 01:28 Universal Time on 24 December falls on the evening of 23 December in New York. This calendar converts every time to the time zone of your device.
What is a lunation?
A lunation is one full cycle of phases, from one new moon to the next. Its average length is 29.53 days, but each one lasts between about 29.27 and 29.83 days, because the Moon's orbit is an ellipse and the Earth's speed around the Sun changes during the year.
Does the calendar work in the southern hemisphere?
The dates and times are the same everywhere. Only the picture changes: in the southern hemisphere the Moon is seen rotated by half a turn. Use the hemisphere switch above the calendar to flip every Moon. The site picks a side from your time zone when you arrive.
How far ahead is the calendar reliable?
The phase times on these pages agree with published almanacs to within about one minute, and we test them against reference tables for 2026 and 2027. The dates themselves are reliable for the whole range of the calendar.
Updated November 11, 2026