we narrowly miss out on a blue moon in the uk tonight. the moon was full on the 2nd of october but it isn’t officially full again until quarter to six tomorrow morning, by which time it will be november. that does mean that november will be a blue moon month though because the full moon will be back on the evening of the thirtieth.

in fact depending on where you are in the world you may have a blue moon in october, november or december.

• in places up to 6 hours behind GMT the blue moon is today. these include hawaii, la and chicago.
• in places where the time zone is set to be from 5 hours behind GMT to 3 hours ahead of it the blue moon will fall on 30th november. these places include new york, london and moscow.
• in places more than 3 hours ahead of GMT the blue moon occurs on 30th december. these places include islamabad, tokyo and sydney.

apparently the “two full moons a month” idea isn’t the only definition of a blue moon. another definition is when there are four rather than three full moons in a season as defined by the solstices and equinoxes. it’s the third moon in the season that’s blue. it seems that the idea that a blue moon is the second full moon in a month has been popularised by a question in the game trivial pursuit.