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blue moon Article

When does a blue moon occur?

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A blue moon is the second full moon in a calendar month, and the period from one full moon to another is about 29 1/2 days. So, when two full moons occur in the same month, the first one is always on the first or second day of the month and the second one is on the 30th or 31st day. Naturally, months with 31 days have a much better chance of hosting a blue moon.

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