The superstition claims Friday the 13th is unlucky. It turns out it's also, very slightly, the most likely — the 13th lands on a Friday more often than on any other weekday. I counted every month in a full 400-year Gregorian cycle (plain Date UTC math) to see how big that edge really is.
Source: [Dev.to](https://dev.to/lucian_lkb_1f009d/is-friday-the-13th-really-more-common-i-counted-400-years-to-find-out-4ph6)