When a calendar says new moon, how many nights is the moon supposed to be full for?

Question

this is the 5th night the moon has been full! is that normal!

Answer 1

The moon actually is full or close to full, for about 5-7 days.
There is a calculation on wikipedia that tells you how long on average each phase lasts.

Answer 2

There are four phases of the moon -- new moon (invisible), first quarter (half moon), full moon, and last quarter (half moon). They're sort of like the four seasons, except the moon takes 29 1/2 days to go through it's cycle, and the earth takes a year.

The new moon occurs when the moon is between the earth and the sun. That means two things: (1) when the moon is in the sky overhead, it's daytime, and you can't see it because of the sun; and (2) when it's nighttime, you can't see the moon because it's on the other side of the planet -- on the daylight side facing the sun.

The full moon occurs when the earth is between the moon and the sun. (Not exactly between, because then we'd have a lunar eclipse.)

There is one moment when that happens, so they could say the full moon occurs at 2:57 a.m. Eastern Time on Tuesday. A few minutes before or after, it's no longer technically a full moon.

But that's just like the Summer Solstice on 21 June. That too has an exact time, like 3:14 p.m. -- the beginning of summer -- and it's the longest day of the year.

But the days are long through May, June, and July. Same thing with the full moon. For a couple of days before, and a couple of days after, the moon looks pretty full.

And there's your five days!

Since the lunar cycle is 29 1/2 days, about 5 are mostly full moon, 5 more are new moon (crescent slivers), 5 are mostly waxing crescent or gibbous moons, and another 5 are waning gibbous or crescent moons.

That leaves about nine or ten days a month for the moon to "transition" from one phase to another, just like we sort of slide from summer into autumn.

That ought to answer your question.

Answer 3

G'day Lady23336,

Thanks for your question.

The full moon only occurs on one night but on the days next to it it might seem full.

The Full Moon is the lunar phase that occurs when the Moon lies on the opposite side of Earth from the Sun. The Moon as seen from the surface of Earth is fully illuminated by the Sun at this time, presenting a "full" round disk to viewers on Earth. As always, only half the total surface of the Moon is illuminated.

Although on average it takes only 27.322 days (sidereal month) for the Moon to complete one orbit around Earth, it requires about two more days than that to again catch up with the Sun. On average, the number of days between Full Moons is about 29.5306 days. The actual number of days may differ from the average number by more than a half day. From one Full Moon to the next, the number of days in one lunation can vary between 29.272 and 29.833 days.

The moon is said to be waning gibbous at the moment with 86% visible at night. It will decline in apparent size until 23 August. The next full moon is due on 7 September.

I have attached some sources for your reference.

Answer 4

Only one night, even if it appears almost the same 2 nights in the row. The exact full moon may happen during the day (or night at the opposite side of earth).

More days?.... you just didn't notice the difference.

Answer 5

When the calendar says "new moon"....you can't actually see the moon in the sky. The earth's shadow covers it completely....

Answer 6

one the other nights it is partially full just not enough to tell