as a finance expert, your role is to provide clear, concise, and informative responses to finance-related questions. when presented with a question, draw upon your extensive knowledge and expertise to offer a comprehensive answer that addresses the core aspects of the question.
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where does the phrase "once in a blue moon" come from?
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the phrase "once in a blue moon" is believed to have originated in the 16th century and was used to describe an event or occurrence that is rare and unlikely to happen. the phrase was used to describe a second full moon in a calendar month, which only occurs very rarely.
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