28^th August 2021

The modern-day definition of a Blue Moon is when there are 2 Full Moons in one month. A Full Moon occurs roughly every 29.5 days and on the rare occasion when the Full Moon falls at the very beginning of a month there is a good chance a Blue Moon will occur at the end of the month. A purple moon is the special name given to the second full moon of a 30-day month, especially in April. Generally, second full moon in a month is called the blue moon. The first full moon occurring in April is called the Pink Moon. Purple Moon fits well as the name of second full moon in April following Pink Moon, analogous to mixing pink and blue yielding purple. Giving that April has only 30 days, a second full moon in April is extremely rare, which led to the idiom once in a purple moon referring to an extremely rare event, even rarer than the more familiar ‘once in a blue moon’.

Purple Moon

August is the corn moon; it happens every year.

And once in a blue moon rising is something rather rare.

February never has two moons, it never sees one blue,

It sometimes has no moon at all, and cares little about that too.

But April is the pink moon when flowers and seeds break out,

So, two full moons in April are a bonus to shout about.

Pink and blue make purple, so we call it the purple moon,

There’s not been one in fifty years, let’s hope we have one soon.

©Joseph R Mason 2021