It currently takes 28 days, but it is getting longer very very slowly.
29.53 days
About 1 month.
The simplest way to put it: Moon phases are simply the passing of the lunar daytime and night across the moon's surface over the course of one month. One entire lunar day is equal to one full set of phases. [Note: the earth's shadow has absolutely nothing to do with the moon's phases.]
Any moon apart from the new moon can be seen in the night sky, although the only moon phase that is above the horizon the entire night is the full moon. The gibbous phases either rise just before sunset or set after sunrise, the quarter phases either rise or set at midnight and the crescent phases either rise shortly before sunrise or set shortly before sunset.
29.5 days
No the sun doesn't have any phases because its not revolving around anything.
every month
Since the phases repeat continuously throughout the lifetime of a person, it's hard to saywhere the beginning of the cycle is.Many cultures consider the beginning to be the phase where you can't see any of the moon at all.Which leads naturally to the name by which that phase is commonly known ... "New Moon".If you accept that point as the beginning of the cycle, then the phase in the middle of the cycleis the "Full Moon".
29 days, 12 hours and 44 minutes. This is not the same as the time taken for the moon to make one orbit of the earth though. Relative to the background stars and ignoring the earth position relative to our sun, the moon takes 27 days 7 hours and 43 minutes to orbit the earth - the sidereal orbit. During this time, the earth has progressed around the sun a little, on its orbit around the sun. For the moon to get back to exactly the right phase, it takes a little longer, 29 days, 12 hours and 44 minutes in total from full moon to the next full moon. This is known as the synodic period. The moon will have made just over one orbit relative to the background stars, and will have moved round slightly to be in front of some different stars to those at the previous full moon.
Every month. One month, give or take is when the moon goes through its full cycle. From new moon to [waxing crescent] to first quarter (week one) then to [waxing gibbous] to full moon (week two) then to [waning gibbous] to third quarter (week three) to [waning crescent] and finally by the end of the fourth week, new moon again.
sunrise
A full moon rises at sunset and sets at sunrise, appearing on the opposite side of the sky as the sun. This is because a full moon is directly opposite the sun in the sky.