Just a woman who loves Snoopy and Halloween shirt

Unlike many people think, blue moon is not inherently blue moon phenomenon but this is the name of the second full moon in a month. Normally, the moon is only round on the full moon day, but if there are more, people call it the blue moon. The blue moon phenomenon will usually repeat after 2-3 years due to the difference between lunar and solar cycles. But because in 2020, the blue moon phenomenon will appear on Halloween night, making this event even more special.