"31 August 2012 was the night when the earth witnessed the blue moon, the second full moon in a month" Therefore within a month of the blue moon, there would be two occurences of full moon, more likely once in the beginning and another one at the end of the month.
Though the statement looks somewhat correct, the truth might be invalid. If we notice, the word moon and month are somewhat different, hence the rareness of the event. But, if we carefully look through deeply into this statement, we could infere that the counting of days in A MONTH (moon) was not actually defined by the moon's appearences, but rather by the counting of days to fit a year. That a year should be about 365-6 days , which then divided by twelve then distributed to each cluster, called month. Thus, a month consists of 28-31 days. But why 12? when it could be easily devided by any other number? We know that there was once in roman era, a year consisted only of 8 months. and then much later, the months were added.
Had we used Lunar Calendar, blue moon would highly be improbable, as a month is the completion of moon phases ; wanning and waxing. and crescent is the start and the end. and through counting, there's either only 29 or 30 days in a month. So, there would be only one occurence of full moon in a month.
Therefore, in solar calendar, a month does not immidiately define its meaning.
then the questions...
1. What was initially defined as 'a month' during the conception of solar calendar? What happened then?
2. As it also consist of 12 months, what is actually a year in lunar calendar?
3. What would matter to earth if a year is not about its revolution towards the sun? What actually repeats?
