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 2001-11-16The 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.