"Once in a blue moon..."
Created | Updated Apr 11, 2002
three lunar months and hence three full-moons. Each full moon is given a
name, for example - the Halvest moon is the full-moon before it is time to
halvest the crops. As with an extra day at leap-year, there is occasionally a
season which contains four full-moons. It is the THIRD moon in a four moon
season which is called the Blue-Moon.