Long Night Moon Also A Blue Moon

The moon is full at 12:28 p.m. today, rising over Baltimore at 4:38 p.m. As the third full moon since the autumn equinox, this one’s called the Long Night Moon, or the Moon Before Yule.

But you could apply the same names to the next full moon, which occurs Dec. 21, just 15 hours BEFORE the winter solstice. As the third full moon in a rare season with four, this one fits the original definition for a Blue Moon.

Popular usage has since attached the label to the second full moon in one calendar month.