Date and time representation by country

See also: Calendar date

Different conventions exist around the world for date and time representation, both written and spoken.

Differences

Differences can exist in:

• The calendar that is used.
• The order in which the year, month and day are represented.
• How weeks are identified.
• Whether the 24-hour clock, 12-hour clock or 6-hour clock is used.
• The punctuation used to separate elements in all-numeric dates and times.

ISO 8601

Main article: ISO 8601

International standard ISO 8601 (Representation of dates and times) defines unambiguous written all-numeric big-endian formats for dates, such as 1999-12-31 for 31 December 1999, and time, such as 23:59:59 for 23 hours, 59 minutes, and 59 seconds (one second before midnight).

These standards notations have been adopted by many countries as a national standard, e.g., BS EN 28601 in the UK and similarly in other EU countries, ANSI INCITS 30-1997 (R2008), and FIPS PUB 4-2 in the United States (FIPS PUB 4-2 withdrawn in United States 2008-09-02).^[1] They are, in particular, increasingly widely used in computer applications, since the most to least significant digit order provides a simple method to order and sort time readings.

Most common usage

See also: Category:Date and time representation by country

Date

See also: Date format by country

In terms of dates, most countries use the "day month year" format. In terms of people the big-endian form is also very common, since that is used in East Asia, Iran and partially in India.

Time

The 24-hour clock enjoys broad everyday usage in most countries outside North America, Australia and the Philippines. When a time is written down or displayed, the 24-hour notation is used in these countries^[which?] almost exclusively. Some regions, for example, most German, French and Romanian speakers use the 24-hour clock today even when speaking casually; in other countries the 12-hour clock is used more often in spoken form, often with an appendix indicating whether the time refers to the morning or afternoon, as opposed to the 24-hour clock in written form. People are used to converting between the two notations^{[citation needed]} with the simple mental calculation of adding or subtracting 12, and most perceive "three o'clock" and "15:00" simply as synonyms, so in spoken language a person may often pronounce time in 12-hour notation, even when reading a 24-hour display.

In other English-speaking regions, particularly former colonies of the United Kingdom, the 12-hour clock and 24-hour are used interchangeably in formal communications.

It is not uncommon that the same person would use the 24-hour clock in spoken language when referring to an exact point in time ("The train leaves at fourteen forty-five …"), while using some variant of the 12-hour notation to refer vaguely to a time ("… so I will be back tonight sometime after five.").

See also

• Calendar date
• Common Locale Data Repository – a database that covers national date and time notations
• ISO 8601 – International standard date and time notation
• Taiwanese date format

References

1. ^ itl.nist.gov