Next principal phases
Moon calendar: January 2026
Sun
Mon
Tue
Wed
Thu
Fri
Sat
1
2
3Full
4
5
6
7
8
9
10Last Quarter
11
12
13
14
15
16
17
18New
19
20
21
22
23
24
25
261st Quarter
27
28
29
30
31
Disc shows the Moon at local noon each day; labels mark days with a principal phase in your time zone.
Why the Moon has phases
The Sun always lights exactly half of the Moon. What changes is how much of that lit half faces us. Drag the Moon around its orbit (viewed from above the North Pole, sunlight coming from the right):
First Quarter
50% of the disc lit, as seen from Earth.
Between Earth and Sun, the lit half faces away: new moon. On the far side, it faces us: full moon. Halfway, we see half of it lit: the quarters, named for being a quarter of the way round the orbit, not for showing a quarter of the disc.
Questions people ask
What is the moon phase today?
Shown at the top of this page, calculated for the current moment from your device clock using Jean Meeus's astronomical algorithms. The illuminated percentage is the share of the Moon's visible disc that is sunlit.
How accurate are these moon phase times?
Principal phases (new, first quarter, full, last quarter) are computed to within a couple of minutes of the times published by the US Naval Observatory. Times are shown in your local time zone.
Does the Moon look the same in the Southern Hemisphere?
The phase and percentage are the same everywhere on Earth at the same moment, but viewed from the Southern Hemisphere the Moon appears upside down compared with the north, so a waxing crescent is lit on the left. Use the hemisphere switch to flip the picture.
How long is a lunar cycle?
On average 29.53 days from one new moon to the next (the synodic month). Individual cycles vary by several hours because the Moon's orbit is elliptical.
What does "waxing" and "waning" mean?
Waxing means the lit part is growing (from new moon towards full); waning means it is shrinking (from full back to new). Gibbous means more than half lit; crescent means less than half.