Horror chracters it’s the most wonderful time of the year Halloween shirt

The night sky on Halloween will be illuminated by a blue moon, the second full moon in a month. The relatively rare occurrence happens once every two and a half years on average, according to NASA’s National Space Science Data Center. Every month has a full moon, but because the lunar cycle and the calendar year aren’t perfectly synched, about every three years we wind up with two in the same calendar month.