Calendar date

The name that a calendar gives to a day.

Even for one calendar (such as the Gregorian). The date may take different forms. Eg.

 16 November 2001
 November 16, 2001
 11/16/2001   - used in places with European influence
 16/11/2001   - used in places with American influence
 2001 November 16
 2001-11-16

The last of these is the ISO 8601 [International Standard]? form, agreed by over 100 countries. [A short list of the major users]. This format is unambiguous and should now be the default way of working.