Blue Moons and Fairy Moons

At some point you may have heard the saying, once in a blue moon. "oh you will lend money but only once in a blue moon" It's an expression we use to say you do not do it very often though.
But what is a blue moon and how frequent are they really?
I've read so many different ways of describing how to spot when there is a blue moon. for instance:

"this occurs when four full moons fall within the same season (as regular seasons only have 3 full moons, the fourth full moon between solstice and equinox, or vice versa, is the Blue Moon)." - [You must be registered and logged in to see this link.]

"A blue moon can refer to the third full moon in a season with four full moons." found at wikipedia.



The way I remember it is that it is the second full moon in a month. Normally each month only contains only one full moon, to a total of twelve in a year. However, because we have a few days left over in our calender year, Every few years (two and a half roughly) we get an extra moon.
So when we say once in a blue moon we are really saying once every two and a half years... that's not really so bad is it?

For some reason a lot of people seem to think that the blue moon will occur once a year... I think that this miss understanding is because people seem to believe that a full moon will happen every 28 days. Here are the full moons of 2011 and a count of the days between the full moons, watch what happens:

January 18th
Febuary 19th (30 days)
March 19th (29 days)
April 18th (29 days)
May 17th (29 days)
June 15th (29 days)
July 15th (30 days)
August 13th (29 days)
September 12th (30 days)
October 12th (30 days)
November 10th (29 days)
December 10th (30 days)

As you can see from above, it's not every 28 days in fact with just looking at the one year the days seem to have no major pattern. except to say that there are either 29 or 30 days between moons. Impossible to have 13 moons every year!


Last Blue Moon: 31st December 2009
Next Blue Moon: 31st August 2012
And then on: 31st July 2015

But what about the Fairy moons?
Fairy moons, or Sidhe Moons, are the opposite of blue moons, and again they occur about every two and a half years. A fairy moon is the second dark moon in a month (the point when there is no moon in the sky to our eyes - obviously there is always a moon in the sky) Some people believe that you should not cast magic on new moons and that you should use that time to relax instead. It is even thought that magic cast on a new moon will turn sour. and that it is worse to cast on a Sidhe moon which is believed to be associated with death. However as with all things, others will argue that you can cast at any time and that the Sidhe moon like the blue moon will make the magic more powerful.

Last Sidhe moon: 30th July 2011
Next Sidhe Moon: 30th January 2014
And then on: 30th October 2016




Useful site link for finding out moon phases: [You must be registered and logged in to see this link.]