• hakase@sh.itjust.works
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    1 year ago

    Fun fact: while a much more often occurrence than once in a lifetime, “Thursday the 20th” is tied with “Saturday the 20th” as the least-likely combination of days of the week with the 20th day of the month, even though you’d think the chances would be exactly 1/7.

    Here’s the math about the Gregorian calendar that explains why. (Even though the post is about Friday the 13th, it straightforwardly can be applied to any other day/date combination as well.)

    • Ertebolle@kbin.social
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      1 year ago

      Interesting. But the difference is 4 days over a 400-year cycle, i.e., in a typical human lifespan you’ll maybe experience one more Thursday the 20th than Friday the 20th.