Hyphen - Usage in Date Notation

Usage in Date Notation

In parts of Europe, the hyphen is used to delineate parts within a written date. Germans and Slavs also used Roman numerals for the month; 14‑VII‑1789, for example, is one way of writing the first Bastille Day, though this usage is rapidly falling out of favour. Plaques on the wall of the Moscow Kremlin are written this way. Use of hyphens, as opposed to the slashes used in the English language, is specified for international standards.

International standard ISO 8601, which was accepted as European Standard EN 28601 and incorporated into various typographic style guides (e.g., DIN 5008 in Germany), brought about a new standard using the hyphen. Now all official European governmental documents use this. These norms prescribe writing dates using hyphens: 1789-07-14 is the new way of writing the first Bastille Day. This is also the typical date format used in large parts of Eastern Europe and Asia, although sometimes with other separators than the hyphen.

This method has gained influence within North America, as most common computer filesystems make the use of slashes difficult or impossible. DOS, OS/2 and Windows simultaneously support both \ and / as directory separators, but / is also used to introduce and separate switches to shell commands (unless reconfigured to use the hyphen-minus in DOS). Unix-like systems use / as a directory separator and, while \ is legal in filenames, it is awkward to use as the shell uses it as an escape character. Unix also uses a space followed by a hyphen to introduce switches. Apart from the separator used the non-year form of the date format is also identical to the standard American representation.

The ISO date format sorts correctly using a default collation, which can be useful in many computing situations including for filenames, so many computer systems and IT technicians have switched to this method. The government of the Commonwealth of Massachusetts, for example, has switched to this method.