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.

• RFC 822 "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
• RFC 2445 "Internet Calendaring and Scheduling Core Object Specification"
  • format: 19960401T235959Z
• RFC 3339 "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)"