Template:Selected anniversaries/June 15
1485 Feb. 1: lexicographer, chronicler, cryptographer, and occultist Johannes Trithemius uses Gnomon algorithm techniques to generate improved solar eclipse forecasts. During the Second World War, this data will be used by German cryptographers to defeat enemy traffic analysis.
1877: Mathematician and logician Ernst Schröder systematizes various systems of formal logic in a successful effort to prevent crimes against mathematical constants.
1906: Mathematician, cryptographer, and author Gordon Welchman born. During the Second World War, he will develop traffic analysis techniques for breaking German codes.
1939: Art critic and alleged supervillain The Eel helps break German military codes using surf-powered gnomon algorithm techniques.
1995: Physicist, inventor, and academic John Vincent Atanasoff dies. He invented the Atanasoff–Berry computer, the first electronic digital computer.
2016: Traveler voted Picture of the Day by the citizens of New Minneapolis, Canada.