Date and time notation by country
Encyclopedia
Different conventions exist around the world for date
and time
representation, both written and spoken.
(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PUB 4-2 in the United States (FIPS PUB 4-2 withdrawn in United States 2008-09-02). 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.
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 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 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.").
Calendar date
A date in a calendar is a reference to a particular day represented within a calendar system. The calendar date allows the specific day to be identified. The number of days between two dates may be calculated. For example, "24 " is ten days after "14 " in the Gregorian calendar. The date of a...
and time
Time
Time is a part of the measuring system used to sequence events, to compare the durations of events and the intervals between them, and to quantify rates of change such as the motions of objects....
representation, both written and spoken.
Differences
Differences can exist in:- The calendarCalendarA calendar is a system of organizing days for social, religious, commercial, or administrative purposes. This is done by giving names to periods of time, typically days, weeks, months, and years. The name given to each day is known as a date. Periods in a calendar are usually, though not...
that is used. - The order in which the yearYearA year is the orbital period of the Earth moving around the Sun. For an observer on Earth, this corresponds to the period it takes the Sun to complete one course throughout the zodiac along the ecliptic....
, monthMonthA month is a unit of time, used with calendars, which was first used and invented in Mesopotamia, as a natural period related to the motion of the Moon; month and Moon are cognates. The traditional concept arose with the cycle of moon phases; such months are synodic months and last approximately...
and dayDayA day is a unit of time, commonly defined as an interval equal to 24 hours. It also can mean that portion of the full day during which a location is illuminated by the light of the sun...
are represented. - How weeks are identified.
- Whether the 24-hour clock24-hour clockThe 24-hour clock is a convention of time keeping in which the day runs from midnight to midnight and is divided into 24 hours, indicated by the hours passed since midnight, from 0 to 23. This system is the most commonly used time notation in the world today...
, 12-hour clock12-hour clockThe 12-hour clock is a time conversion convention in which the 24 hours of the day are divided into two periods called ante meridiem and post meridiem...
or 6-hour clock is used. - The punctuationPunctuationPunctuation marks are symbols that indicate the structure and organization of written language, as well as intonation and pauses to be observed when reading aloud.In written English, punctuation is vital to disambiguate the meaning of sentences...
used to separate elements in all-numeric dates and times.
ISO 8601
International standard ISO 8601ISO 8601
ISO 8601 Data elements and interchange formats – Information interchange – Representation of dates and times is an international standard covering the exchange of date and time-related data. It was issued by the International Organization for Standardization and was first published in 1988...
(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
ISO 8601 usage
On the Internet, the World Wide Web Consortium uses ISO 8601 in defining a profile of the standard that restricts the supported date and time formats to reduce the chance of error and the complexity of software....
, e.g., BS EN 28601 in the UK and similarly in other EU countries, ANSI
Ansi
Ansi is a village in Kaarma Parish, Saare County, on the island of Saaremaa, Estonia....
INCITS 30-1997 (R2008), and FIPS
Federal Information Processing Standard
A Federal Information Processing Standard is a publicly announced standardization developed by the United States federal government for use in computer systems by all non-military government agencies and by government contractors, when properly invoked and tailored on a contract...
PUB 4-2 in the United States (FIPS PUB 4-2 withdrawn in United States 2008-09-02). 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.
Date
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 clock24-hour clock
The 24-hour clock is a convention of time keeping in which the day runs from midnight to midnight and is divided into 24 hours, indicated by the hours passed since midnight, from 0 to 23. This system is the most commonly used time notation in the world today...
enjoys broad everyday usage in most countries outside North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
, Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
and the Philippines
Philippines
The Philippines , officially known as the Republic of the Philippines , is a country in Southeast Asia in the western Pacific Ocean. To its north across the Luzon Strait lies Taiwan. West across the South China Sea sits Vietnam...
. When a time is written down or displayed, the 24-hour notation is used in these countries 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 with the simple mental calculation
Mental calculation
Mental calculation comprises arithmetical calculations using only the human brain, with no help from calculators, computers, or pen and paper. People use mental calculation when computing tools are not available, when it is faster than other means of calculation , or in a competition context...
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
12-hour clock
The 12-hour clock is a time conversion convention in which the 24 hours of the day are divided into two periods called ante meridiem and post meridiem...
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 dateCalendar dateA date in a calendar is a reference to a particular day represented within a calendar system. The calendar date allows the specific day to be identified. The number of days between two dates may be calculated. For example, "24 " is ten days after "14 " in the Gregorian calendar. The date of a...
- Common Locale Data RepositoryCommon Locale Data RepositoryThe Common Locale Data Repository Project, often abbreviated as CLDR, is a project of the Unicode Consortium to provide locale data in the XML format for use in computer applications. CLDR contains locale specific information that an operating system will typically provide to applications. CLDR is...
– a database that covers national date and time notations - ISO 8601ISO 8601ISO 8601 Data elements and interchange formats – Information interchange – Representation of dates and times is an international standard covering the exchange of date and time-related data. It was issued by the International Organization for Standardization and was first published in 1988...
– International standard date and time notation - Taiwanese date format