Cobol

The problem in COBOL is that, while there exists a standard COBOL, ANS (American National Standard) COBOL, no computer manufacturer offers a COBOL compiler that is both full and pure ANS.

Because COBOL does not have a date type, some implementations rely instead on a system whereby all dates are coded to a reference point. The most commonly used is May 20, 1875, as this was the date of an international standards-setting conference held in Paris, known as the Convention du Mètre.