Date and time representation by country

Different stylistic conventions and habits exist around the world in order to express date and time in written and spoken language. Examples for such differences include preferences for

• the 24-hour clock or 12-hour clock notation;
• the order in which year, month and day are written;
• the punctuation symbols used to separate elements in numeric representations of time;
• the way in which weeks are identified.

Conventions for expressing date and time can also differ substantially for written communication and spoken language.

ISO 8601 defines an unambiguous written format for date and time. The standard has been adopted as European Norm 28601, and by the national standards organizations of most EU members.

Australia

The 12-hour notation is the default in Australia. 24-hour notation is limited to internal communications within services and organisations. The 24-hour notation is usually referred to as "army time".

Australia has also signed up to use the ISO 8601 notation through the national standard AS 3802:1997.

Austria, Germany, Switzerland

Date

The traditional all-numeric form of writing Gregorian dates in German is the little-endian day-month-year order, using a dot on the line (period or full stop) as the separator (e.g. “31.12.1991” or “15.4.74”). Some typesetters prefer the space after the second dot to be slightly larger than the first. Years can be written with two or four digits; the century may also be replaced by an apostrophe: “31.12.’91”. Numbers may be written with or without leading zero, but commonly they are only discarded in days when literal months are being used (e.g. “09.11.”, but “9. November”). The use of a dot as a separator matches the convention of pronouncing the day and the month as an ordinal number, because ordinal numbers are written in German followed by a dot.

In 1995 in Germany, this traditional notation was replaced in the DIN 5008 standard, which defines common typographic conventions, with the ISO 8601 notation (e.g. “1991-12-31”). The latter is beginning to become popular in some areas, especially computer software, but can not yet be described as very widely used. The expanded form of the date (e.g. “31. Dezember 1991”) continues to use the little-endian order and the ordinal-number dot for the day of the month.

Week numbers according to ISO 8601 and the convention of starting the week on Monday were introduced in the mid 1970s (DIN 1355). These conventions have been widely adhered to by German calendar publishers since then. Week numbers are prominently printed in calendars and are widely used in the business world. It is common to hear people say “I’m still free in week 36” or to have a company write “We expect delivery in week 49”. In contrast to this, television broadcast weeks continue to start on Saturdays, two days before the DIN 1355 week.

Time

In written German, time is expressed practically exclusively in the 24-hour notation (00:00–23:59), using either a colon or a dot on the line as the separators between hours, minutes and seconds. Example: 14:51 or 14.51. The standard separator in Germany was the dot (DIN 1355, DIN 5008) until 1995, when the standards changed it to be the colon, in the interest of compatibility with ISO 8601.

In spoken language, the 24-hour clock has become the dominant form during the second half of the 20th century, especially for formal announcements and exact points in time. Systematic use of the 24-hour clock by German TV announcers, along with the proliferation of digital clocks, may have been a significant factor in this development.

A variant of the 12-hour clock is also used, in particular in informal speech for approximate times. On some radio stations, announcers regularly give the current time on both forms, as in "Es ist jetzt vierzehn Uhr einundfünfzig; neun Minuten vor drei" ("It is now fourteen fifty-one; nine minutes to three").

The variant of the 12-hour clock that is sometimes used in spoken German refers to the fraction of the hour that has already been completed, along with the forthcoming full hour. Examples:

14:00 = "zwei Uhr" (two o'clock)

14:15 = "viertel drei" (quarter three)

14:30 = "halb drei" (half three)

14:45 = "dreiviertel drei" (three-quarter three)

15:00 = "drei Uhr" (three o'clock)

Alternatively, the 1–30 min interval to the nearest full hour can be given as in

14:15 = "viertel nach zwei" (quarter past two)

14:45 = "viertel vor drei" (quarter to three), in the South also "viertel auf drei"

Note that these phrases are exlusive to the 12-hour clock, just as the "(hour) Uhr (minutes)" format is exclusive to the 24-hour clock.

Canada

In Canada, similar to the United States, the 12-hour clock is used in ordinary life by the English-speaking population. French speakers in Quebec, however, often use the 24-hour clock. 24-hour time is also very common in the capital, Ottawa, Ontario. The 24-hour clock is also routinely used in the health care setting, such as hospitals.

Canada has also signed up to use the ISO 8601 format for date and time through national standard CSA Z234.5:1989. The time format used in the standard is also referred to by some people as "Metric Time" as it happened at about the same time that Canada adopted various Metric measurements.

Greater China

Date

The date format follows the Chinese hierarchical system, which has traditionally been big-endian. Consequently, it conforms to ISO 8601 — year first, month next, and day last. Example: 2006-01-29. The hyphen is often replaced with other separators, such as a dot or a forward slash. Example: 2006.01.29. A leading zero is optional in practice. Chinese characters that mean year, month, and day are often used as separators too. Example: 2006年01月29日.

Since the characters clearly label the date, the year may be abbreviated to two digits when this format is used. The exception to this guideline is in Taiwan, where a separate calendrical system is used, with years numbered to the founding of the Republic of China in 1912. Thus, the year 2006 corresponds to the "95th year of the Republic" or in Chinese Minguo 95 (民國95年). In official contexts, this system is always used, while in informal contexts, the Gregorian calendar is sometimes used. To avoid confusion, the Gregorian year is always written out in full in Taiwan. Example: 95.01.29 refers to 2006-01-29, not 1995-01-29 (which would be rendered as 84.01.29). Another means to distinguish between the two systems is to append the terms Gongyuan (公元, common era) and Minguo (民國, Republic) before the year. Example: 2006 is rendered as either 公元2006年 or 民國95年.

The day of the week is often appended to the date and commonly enclosed in parentheses. Example: 2006年01月29日 (星期天).

In speech, the date is spoken in the same format as it is written. Using the previous example: 2006 (èrlínglíngliù) 年 (nián) 01 (yī) 月 (yuè) 29 (èrshíjiǔ) 日 (rì) 星期天 (xīngqītiān).

Haò (simplified Chinese: 号; traditional Chinese: 號) is an alternative character used to express the day of the month instead of rì (Chinese: 日). It is sometimes used in written Chinese and often used in spoken Chinese. Using the previous example: 2006 (èrlínglíngliù) 年 (nián) 01 (yī) 月 (yuè) 29 (èrshíjiǔ) 號 (haò) 星期天 (xīngqītiān). Haò is also used when the month is understood from context, i.e.: 29號 or the 29th.

Dates written in Hong Kong and Macau are often formatted in the DD.MM.YYYY style due to European influences. Nonetheless, the Chinese form of the dates is still read in the same way as described above.

Time

Both the 12-hour and 24-hour notations are used in spoken and written Chinese. However, to avoid confusion, time on schedules and public notices are typically formatted in the 24-hour system. Example: 19:45. Chinese characters that mean hour (simplified Chinese: 时; traditional Chinese: 時; pinyin: shí) and minute (Chinese: 分; pinyin: fēn) are sometimes used instead of the standard colon. Example: 19時45分. 正 (zhèng) is used to mean exactly on the hour. Example: 19時正.

It is not uncommon to see Chinese numerals instead of Arabic numbers, however tourist attractions will usually use Arabic numerals for the convenience of foreigners.

Spoken Chinese predominately uses the 12-hour system and follows the same concept as A.M. (上午 shàngwŭ) and P.M. (下午 xiàwŭ). However, shàngwŭ and xiàwŭ precede the time. Example: 下午7:45 or 下午7點45分 (xiàwǔ qīdiǎn sìshíwǔfēn). Diǎn (simplified Chinese: 点; traditional Chinese: 點) is a variation of shí and typically used in speech and often in writing. Zhōng (simplified Chinese: 钟; traditional Chinese: 鐘), which literally means clock, can be added to a time phrase, usually when it contains either only hours or only minutes. Example: 7點鐘 or 12分鐘. If the number of minutes is less than ten, the preceding zero is included in speech. Example: 上午8:05 (shàngwŭ bādiǎn língwǔfēn). Time written in the 24-hour system can be read as is. Example: 19:45 (shíjiǔdiǎn sìshíwǔfēn).

A sample of other phrases that are often used to better describe the time-frame of day are listed below:

Traditional	Simplified	Pinyin	Meaning
淩晨	凌晨	língchén	very early morning (after midnight)
早上		zaǒshàng	early morning
上午		shàngwŭ	AM or before noon
中午 or 正午		zhōngwŭ or zhèngwŭ	noon or midday
下午		xiàwŭ	PM or afternoon
黃昏		huánghūn	earlier evening
傍晚		bàngwǎn	earlier evening
晚上		wǎnshàng	evening or night
深夜		shēnyè	late night

Examples:

03:00 = 淩晨3點鐘 (língchén sāndiǎnzhōng)

19:00 = 黃昏7點鐘 (huánghūn qīdiǎnzhōng)

Note: These phrases that describe the time-frame of day are used only with the 12-hour system.

Time can alternatively be expressed as a fraction of the hour in speech. The traditional Chinese unit of time, the 刻 (kè), is contemporarily used to mean "quarter of an hour". A quarter-after is 一刻 (yīkè) or 多一刻 (duō yīkè). The characters literally mean "a kè" or "an additional kè", respectively. A quarter-to is 差一刻 (chā yīkè). 差一刻 literally means "less a kè". 半 (bàn), which means half, is used in conjunction with the relative hour to mean "at the half-hour". Examples:

6:45 = 7點差一刻 (bādiǎn chā yīkè)

8:15 = 8點多一刻 (bādiǎn duō yīkè)

9:30 = 9點半 (jiǔdiǎn bàn)

Attention must be drawn to the time 02:00. It is written as 2時 (èrshí) but always read as liǎngdiǎn. The number two, 二 (èr), takes the form of 兩 (liǎng) when followed by a measure word, in this case, 點 (diǎn). Note that this does not apply to 12:00. Noon is 12點鐘 (shí èr diǎnzhōng) or 正午 (zhèngwŭ) or 午時 (wŭshí). Midnight, on the other hand, is 淩晨12點鐘 (língchén shí èr diǎnzhōng) or 零時 (língshí), which literally means zero hour.

Cantonese has an additional method of expressing time as a fraction of the hour. This system divides the hour into 12 units, each five minutes long. Each unit, therefore, corresponds to one of the numbers written on an analogue clock. The character for this unit is uncertain since it is only used in speech, however the Cantonese pronunciation is ji6 and homonymous to the character 字 (zì, Cantonese: ji6). This method can be used in two ways - with the relative hour and without. When the relative hour is included, the unit must be preceded with the measure word 個 (ge, Cantonese: go3). Example: 3:05 is 3點1個字 (sāndiǎn yīgezì, Cantonese: saam1 dim2 yat1 go3 ji6). When the relative hour is not included, the unit is omitted as well; the position of the minute hand is described instead, using the verb 踏 (tà, Cantonese: daap6), which means "resting on top of" in this context. Examples:

five-after = 踏1 (tà yī, Cantonese: daap6 yat1)

ten-after = 踏2 (tà èr, Cantonese: daap6 yi6)

fifteen-to = 踏9 (tà jiǔ, Cantonese: daap6 gau2)

ten-to = 踏10 (tà shí, Cantonese: daap6 sup6)

The half-hour mark is never described using this unit of five minutes, however. 3:30 is still 3點半 (sāndiǎn bàn, Cantonese: saam1 dim2 bun3), as previously described. Half-past the hour is 踏半 (tàbàn, Cantonese: daap6 bun3).

Ethiopia

In Ethiopia a 12-hour clock is still used that counts 12, 1, 2, ..., 10, 11 from dawn till dusk, and again 12, 1, 2, ..., 10, 11 from dusk to dawn. Unlike the convention in most countries, the start of the day is dawn, rather than midnight.

France

In France, the all-numeric form for dates is in the order day-month-year, using a slash as the separator. Example: 31/12/1992 or 31/12/92. Years can be written with two or four digits, and numbers may be written with or without leading zero.

The 24-hour notation is used in writing with an h as a separator (h for heure, meaning hour). Example: 14 h 05. Though the correct form includes spaces on both sides of the h, it is common to see them omitted: 14h05. The minutes are written with two digits; the hour numbers can be written with or without leading zero.

Sweden

In Sweden the ISO 8601 standard is closely followed in most written Swedish. Dates are generally and officially written for example "2006-12-31", but the older forms "31/12-2006", "31/12 2006", "31/12-06" or "31/12/06" are frequently seen informally. The long form as in "31 december 2006" is also sometimes used in writings, and almost always in speech (although the date is pronounced as an ordinal number). Both in the older short forms and the long form, written and spoken, the year is often left out. Numbering of weeks are frequently used in companies and schools and are simply expressed as in "(vecka) 32" ((week) 32) in both writing and speech. On labels and in computers' notation, the year may also be included, as in "2006-30". As in the ISO standard, the week begins with a Monday and week 1 is the week containing the year's first Thursday.

Times are written without notable exceptions with the 24-hour clock, although seconds are usually left out. Example: 23:59, or sometimes 23:59:00. In spoken Swedish however, the 12-hour clock is much more common. Usually time is expressed in 5-minute intervals (rounded so that it can be evenly divided by 5) like this: <the hour>, <5, 10 or 20 [minutes]> past <the hour>, a quarter <past, to> <the hour/following hour>, half <the following hour> or five <past, to> half <the following hour>. More accurately like this: <1-29 [minutes]> past <the hour>, half <the following hour> or <29-1 [minutes]> to <the following hour>. In these styles, the word for "minutes" is usually but not always left out. Finally the written notation can be pronounced as is: <the hour> <the minute>, although this isn't very common in everyday conversation. The 24-hour time is always applied on the last form, may be applied to the second form and is never used with rounded time as in the first form. Seconds are very seldom expressed at all in speech. Example: 14:27 may be pronounced as "fem i halv tre" (five to half three), "tjugosju (minuter) över två/fjorton" (twenty seven (minutes) past two/fourteen) or "fjorton tjugosju" (fourteen twenty seven). 16:00 may be pronounced as "fyra" (four) or "sexton" (sixteen).

Thailand

In Thailand, next to the 12-hour and 24-hour clock system, a 6-hour clock system is also used, especially in spoken language. It counts 4 times from 1 to 6, with different additional words to make the distinction for night, morning, afternoon and evening.

Thailand mainly uses the Buddhist Era which is 543 years ahead of the Gregorian year. The year AD 2006 is indicated as 2549 BE in Thailand.

Thailand also adopted ISO 8601 under national standard: TIS 1111:2535 in 1992.

United Kingdom

Dates are written traditionally in day-month-year order, using a slash as the separator. This order is used in both the traditional all-numeric date (e.g., "31/12/99") as well as in the expanded form (e.g., "31 December 1999"). Although ISO 8601 has been adopted as a British Standard, the use of its big-endian date notation remains mostly restricted to specialist use (e.g., use-by dates on medical products) and computer applications.

Both the 12-hour and 24-hour notations are used in the United Kingdom. The 12-hour notation is still widely used in ordinary life, written communication and displays and continues to be used in informal spoken language. The 24-hour notation is used on timetables and some written communication. The 24-hour notation is used more commonly than in the United States, but not quite as commonly as in much of the non-English speaking world.

Weeks are generally referred to by the date on which they start, e.g., "week commencing 5 March". The beginning of the week is commonly considered to be Monday.

United States

Date

The United States is perhaps the only country in which dates are written in a middle-endian order, the month-day-year order, that is in neither descending or ascending order of significance. This order is used in both the traditional all-numeric date (e.g., "12/31/99") (said with all cardinal numbers) as well as in the expanded form (e.g., "December 31, 1999") (said with the year as a cardinal number and the day as an ordinal number), with the historical rationale that it is indeed big-endian with respect to the month and day, as the year was often of lesser importance. The most commonly used separator in the all-numeric form is the slash, though the dash is also common. If the day-month-year order is used at all, the month is usually written as a name, as in "12-Dec-1999".

The ISO 8601 date notation YYYY-MM-DD is beginning to become popular in some computer applications. It may be considered less of a break with tradition by U.S. users (compared to Europeans) because it preserves the familiar month-day order. Two US standards mandate the use of ISO 8601-like formats: ANSI X3.30-1985(R1991) and NIST FIPS 4-1, the earliest is traceable back to 1968.

Weeks are generally referred to by the date of some day within that week (e.g. "the week of March 5"), rather than by a week number. Calendars mostly show Sunday as the first day of the week.

Time

The United States differs from other countries in that it uses the 12-hour notation almost exclusively, not only in spoken language but also in writing, even on timetables, airline tickets and with some computer software. The suffix "a.m." or "p.m." is appended universally in written language. Where this is inconvenient typographically (e.g. in dense tables), different fonts or colors are sometimes used instead of a.m./p.m. Due to ambiguity of the 12-hour notation at noon and especially midnight, it is customary in the U.S. to avoid scheduling events at exactly 12:00 a.m. or p.m.. The time "11:59 PM" is often used to remove ambiguity.

The 24-hour notation is rarely used so far in the U.S. in public communication. It is best known there for its use by the military, and therefore commonly called "military time". In U.S. military use, 24-hour time is traditionally written without a colon (1800 instead of 18:00) and in spoken language followed by the word "hours" (i.e. "eighteen hundred hours"). The 24-hour notation is also widely used by astronomers and some other communities (public safety, transport, aerospace) where exact and unambiguous communication of time is critical. It is also widely used with computers, but less commonly with applications targeted at non-specialist end users.

Some style guides and most people suggest not to use a leading zero with a single-digit hour; for example, "3:52 p.m." is preferred over "03:52 p.m.". Many (but only those that can also display) digital clocks nevertheless use a leading zero. (The leading zero is more commonly used with the 24-hour notation; especially in computer applications because it can help to maintain column alignment in tables and correct sorting order.)

Pronunciation

Times of day ending in :00 minutes may be pronounced in English as the numbered hour followed by o'clock (e.g., 10:00 ten o'clock, 2:00 two o'clock, 4:00 four o'clock etc). This may be followed by the a.m. or p.m. designator, or may not be if obvious. O'clock itself may be omitted, leaving a time like four a.m. or four p.m.. :01 through :09 are usually pronounced as oh one through oh nine. :10 through :59 are their usual number-words.

East Africa

In many East African languages, the start of the daily time system is at dawn, not midnight. Thus what would be seven o'clock in the morning in English becomes one o'clock in the morning in Swahili and other East African languages. This also affects the date: the whole night is the same date as the preceding day. For example, Tuesday does not become Wednesday until morning breaks, rather than changing at midnight. For multi-lingual speakers in East Africa, the convention is to use the time system applicable to the language one happens to be speaking at the time. A person speaking of an early morning event, in English, would report that it happened at eight o'clock, however in repeating the same facts in Swahili, would state that the events occurred at "saa mbili" (two o'clock).

Other regions

The 24-hour clock enjoys broad everyday usage in most African, Asian, Oceanic, European and many Latin American countries. When a time is written down or displayed, the 24-hour notation is used in these countries almost exclusively. The 12-hour clock remains in some regions commonly used in informal language, while, for example, most German, French and Romanian speakers use the 24-hour clock today even when speaking casually.

It is not uncommon that the same person would use the 24-hour notation 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."). People are used to converting between the two notations without requiring mental arithmetic, and most perceive "three o'clock" and "15:00" simply as synonyms.

See also

• 24-hour clock
• 12-hour clock
• Thai six-hour clock
• ISO 8601 – International standard date and time notation