About 3 days before the new moon, the Moon is a crescent in the eastern sky before dawn. The "before dawn" part is why people seldom see the "waning crescent" Moon.
Just a second ... let me look ... Right now it's a waning crescent, just a few days before New Moon. (8:00 PM CST, March 10, 2010)
Sunlight reflected from Earth, especially that reflected onto the dark side of the Moon. For a few days before and after each new moon, this doubly reflected light is powerful enough to make the whole Moon visible, producing the effect, in the case of the new moon, of "the new moon holding the old moon in her arms."
A full lunar (Moon) cycle - from one full moon to the next - takes about 29 1/2 days. While the moment of the new moon can be defined and calculated to the minute, probably to the second, if you just look at the Moon it will look "new" for a few days.
Mare Crisium is illuminated from a few days after the New Moon until a few days after the Full Moon.
A full moon typically lasts for just one night, as it is the moment when the moon is completely illuminated by the sun in the sky. However, the effects and visibility of the full moon can be felt for a few days before and after its peak, which is often called the "full moon phase."
For a few days following the new moon.
Sometimes the dark part of the moon is illuminated by the reflection of sunlight off the Earth. It is called Earthshine. Check this site http://home.hiwaay.net/~krcool/Astro/moon/earthshine/
The waning crescent moon occurs just before the new moon, as the illuminated portion of the moon visible from Earth decreases in size. It is the final phase of the lunar cycle before the start of a new cycle.
The full moon only actually lasts one day, so only one day in a month is there a full moon (although it will look full for a few days).
The two best days to look for job advertisements in a daily newspaper are typically Wednesday and Sunday. Many companies choose these days to advertise job opportunities because of higher readership and circulation.
You can't see the moon during the 12 to 30 hours before and after the New Moon. So that's anywhere from 1 to 2-1/2 days during the month, depending on the exact angle of the ecliptic to the horizon, and the moon's orbital inclination relative to the ecliptic. (Those things change from month to month.)
Jupiter