Actually, it’s Sir Aurthur Conan Doyle’s birthday.
But, since he is Holmes, in a way, well… Anyway, this comes from the Writer’s Almanac:
It’s the birthday of novelist and short story writer Arthur Conan Doyle, (books by this author) born in Edinburgh, Scotland (1859). Conan Doyle studied medicine at the University of Edinburgh where he met Doctor Joseph Bell, whose amazing deductions about the history of his patients fascinated the young student. After completing his studies, Conan Doyle served as a ship’s doctor on voyages to Greenland and West Africa, and eventually opened his own practice. In his spare moments, he began writing. Calling on his memories of Doctor Bell, Conan Doyle created a detective who used his great powers of deduction to solve crimes. The first such story, A Study in Scarlet, introduced the detective Sherlock Holmes and his sidekick, Doctor Watson, in 1887. All told, Conan Doyle wrote 56 Sherlock Holmes stories and four Holmes novels.