an old phase or even a total eclipse
That is the first quarter moon which looks like a half moon.
New Moon Phase
In the new Moon phase.
The moon will disappear when it is in the new moon phase, as ironic as that sounds.
This question almost deserves to be moved to the "Adds no value" category, since anyone looking up the answer on some day other than the one it was answered (correctly) on will see an answer that is very, very likely to be wrong. Google Calendar includes a moon phase calendar. As do many, if not most, other calendars. Look on one of them.
After a week from new moon, you'll see a half moon. This is more correctly called the First Quarter phase of the Moon.
That is the first quarter moon which looks like a half moon.
First Quarter does.
The First Quarter moon
Two weeks after the waning gibbous phase of the moon you will see a new moon.
Tonight the 16th November 2009 is a new Moon, so last night there should have been no Moon visible.
New Moon.
The New Moon always occurs very close to the moon's "new moon" phase.
On a New Moon PhaseOn a New Moon Phase
The Moon's phase is New Moon.
New Moon Phase
New Moon Phase