How many weeks are there from a waxing crescent moon to a waning crescent moon?

There are approximately four weeks between a waxing crescent moon and a waning crescent moon. This period encompasses the entire lunar cycle, which lasts about 29.5 days. The waxing crescent phase occurs shortly after the new moon, while the waning crescent phase occurs just before the next new moon. Therefore, the transition includes the first quarter, full moon, and last quarter phases.