Date and time notation in Japan has historically followed the

Japanese calendar Japanese calendar types have included a range of official and unofficial systems. At present, Japan uses the Gregorian calendar together with year designations stating the year of the reign of the current Emperor. The written form starts with t ...

and the ''

nengō The , also known as , is the first of the two elements that identify years in the Japanese era calendar scheme. The second element is a number which indicates the year number within the era (with the first year being ""), followed by the literal ...

'' system of counting years. At the beginning of the

Meiji period The is an era of Japanese history that extended from October 23, 1868 to July 30, 1912. The Meiji era was the first half of the Empire of Japan, when the Japanese people moved from being an isolated feudal society at risk of colonization ...

, Japan switched to the

Gregorian calendar The Gregorian calendar is the calendar used in most parts of the world. It was introduced in October 1582 by Pope Gregory XIII as a modification of, and replacement for, the Julian calendar. The principal change was to space leap years dif ...

on Wednesday, 1 January 1873, but for much domestic and regional government paperwork, the Japanese year is retained. Japanese people and businesses have also adopted various conventions in accordance with their use of ''

kanji are the logographic Chinese characters taken from the Chinese family of scripts, Chinese script and used in the writing of Japanese language, Japanese. They were made a major part of the Japanese writing system during the time of Old Japanese ...

'', the widespread use of

passenger trains In rail transport, a train (from Old French , from Latin , "to pull, to draw") is a series of connected vehicles that run along a railway track and transport people or freight. Trains are typically pulled or pushed by locomotives (often know ...

, and other aspects of daily life.

Date

The most commonly used date format in Japan is ''"year month day (weekday)"'', with the

Japanese characters The modern Japanese writing system uses a combination of logographic kanji, which are adopted Chinese characters, and syllabic kana. Kana itself consists of a pair of syllabaries: hiragana, used primarily for native or naturalised Japanese wo ...

meaning "year", "month" and "day" inserted after the numerals. Example: for "Wednesday 31 December 2008". The weekday is usually abbreviated to a single character, e.g. for ("Wednesday"), but may also be written in full, then usually without surrounding parentheses. Apart from the

, the Japanese imperial calendar is also used, which bases the year on the current era, which began when the current emperor acceded to the throne. The current era is ''

Reiwa is the current Japanese era name, era of Japan's official calendar. It began on 1 May 2019, the day on which Emperor Akihito's elder son, Naruhito, Enthronement of the Japanese emperor, ascended the throne as the 126th Emperor of Japan. The ...

'' and began in 2019. When using the imperial calendar, the year is prefixed with the era. For example, the above date using the imperial calendar is written as: ; a more direct translation might be: Heisei year 20, Dec 31 (Wed). Either form may be abbreviated as ''yy/mm/dd''; periods as separators are not uncommon either. Examples: , . Ambiguities as to which calendar is used for the year are usually only resolved by the context in which the date appears, but imperial calendar dates may be prefixed with a single character or letter denoting the era, e.g. or . This is a shorthand notation and full dates are often the preferred way of resolving such ambiguities.

Time

Both the 12-hour and 24-hour notations are commonly used in Japan. The

24-hour notation The modern 24-hour clock, popularly referred to in the United States as military time, is the convention of timekeeping in which the day runs from midnight to midnight and is divided into 24 hours. This is indicated by the hours (and minutes) pass ...

is commonly used in Japan, especially in train schedules. The 12-hour notation is also commonly used, by adding ("before noon") or ("after noon") before the time, e.g. for 10 am. Japanese broadcasting and newspapers usually use a modified 12-hour notation in which midnight is (0 am) and noon is (0 pm) and, for example, "quarter past midnight" is . The AM/PM signs are also used, while the sign may be placed either before or after the time (AM10:00 or 10:00AM). Using the Japanese notation, times are written as "", with the characters for "hour" and "minute" (optionally also for "seconds") added after the numerals. It is also common to simply write though. Times past midnight can also be counted past the 24 hour mark, usually when the associated activity spans across midnight. For example, bars or clubs may advertise as being open until "" (i.e. 6 am). This is partly to avoid any ambiguity (6 am versus 6 pm), partly because the closing time is considered part of the previous business day, and perhaps also due to cultural perceptions that the hours of darkness are counted as part of the previous day, rather than dividing the night between one day and the next. Television stations will also frequently use this notation in their late-night scheduling. This 30-hour clock form is rarely used in conversation.

References

{{Asia topic, Date and time notation in Time in Japan Japan