Your geographic location can make a difference to your experience of a Blue Moon. Depending on your longitude you may go through a date change prior to other locations which means the full moon is at the first of your new month and falls at the end of the preceding month somewhere else. The “blue” one is always the 2nd full moon in the same month. The regular full moons of each month all have their own individual names as follows: Moon after Yule, Wolf Moon, Lenten Moon, Egg Moon, Milk Moon, Flower Moon, Hay Moon, Grain Moon, Fruit Moon, Harvest Moon, Hunters’ Moon and Moon Before Yule.
Historically the Blue Moon was considered unlucky and a real nuisance when it occurred at various times of the year and upset scheduling of church festivals. In love songs the Blue Moon is often a symbol of sadness and loneliness.
The first appearance in print of this expression goes back to the time of Shakespeare, when some folks felt that sometimes the moon visually appeared blue in the sky. Although the expression dates all that way back, it has only recently come to mean the second Full Moon in one month. Blue Moon seems to be a truly modern piece of folklore, old folklore it is not, but real folklore it is.