Op vrijdag 31 augustus 2012 11:36:27 UTC+2 schreef Martin Rowley het volgende:
... I wrote something up about 'blue moons' and its changed meaning over
the years here ....
http://weatherfaqs.org.uk/node/161
.... and here is a photo of last night's "blue moon" taken at Gorinchem in the Netherlands
http://www.janvissersweer.nl/ (scroll down to the bottom). The caption repeats the definition you refer to: 2nd full moon in the same month.
Colin Youngs
Brussels