Date and time notation around the world varies.
An approach to harmonize the different notations is the ISO 8601 standard.
Since the Internet is a main enabler of communication between people with different date notation backgrounds, and software is used to facilitate the communication, RFC standards and a W3C tips and discussion paper were published.
"Standard for the Format of Arpa Internet Text Messages" published 1982-08-13 e.g. used for email format: [day ,] 20 Jun 82 14:01:17 "Internet Calendaring and Scheduling Core Object Specification" format: 19960401T235959Z "Date and Time on the Internet: Timestamps" published July 2002 intended use: new internet protocols format: 1982-06-20 W3C: "Use international date format (ISO)"
See also
Date and time representation by country Date code Holocene calendar ISO 8601 usage Time formatting and storage bugs Unix time