Ke (unit)
Encyclopedia
The ke is a traditional Chinese unit of decimal time
lasting approximately a quarter
of a western hour
. Traditionally the ke divides a day into 100 equal intervals of 14.4 minutes (14 m
24 s
). The ke is equivalent to the centiday (c
d
), a non-SI prefixed unit. Ke literally means 'to etch' or 'to cut', and it is part of the noun Kedu which refers to etched-on markings on measuring devices.
Alongside the ke, the ancient Chinese kept time with double hours (traditional 時辰, simplified 时辰, pinyin shíchen) also known as watches. Because one cannot divide 12 double hours into 100 ke evenly, each ke was subdivided into 60 fen (分; pinyin fēn).
There were various attempts to redefine the ke to 96, 108, or 120 so as to divide evenly into 12 double hours. During the Qing dynasty
around the time of the arrival of Jesuit missionaries, the duration of the ke was finally redefined to one ninety-sixth of a day, or exactly one quarter of a western hour. Today ke is the standard Chinese term to refer to a quarter of an hour. In addition, today's fen is currently used to refer not to 1/60 of a ke but rather 1/60 of an hour, or 1 minute.
Decimal time
Decimal time is the representation of the time of day using units which are decimally related. This term is often used to refer specifically to French Revolutionary Time, which divides the day into 10 decimal hours, each decimal hour into 100 decimal minutes and each decimal minute into 100 decimal...
lasting approximately a quarter
Quarter
Quarter is one fourth, ¼, or 25%, and may refer to:*Quarter , a section or area, usually of a town*Quarter , valued at one-fourth of a U.S...
of a western hour
Hour
The hour is a unit of measurement of time. In modern usage, an hour comprises 60 minutes, or 3,600 seconds...
. Traditionally the ke divides a day into 100 equal intervals of 14.4 minutes (14 m
Minute
A minute is a unit of measurement of time or of angle. The minute is a unit of time equal to 1/60th of an hour or 60 seconds. In the UTC time scale, a minute on rare occasions has 59 or 61 seconds; see leap second. The minute is not an SI unit; however, it is accepted for use with SI units...
24 s
Second
The second is a unit of measurement of time, and is the International System of Units base unit of time. It may be measured using a clock....
). The ke is equivalent to the centiday (c
Centi
Centi is a prefix in the metric system denoting a factor of one hundredth. Adopted in 1795, the prefix comes from the Latin centum, meaning hundred. It is mainly used with the metre to express lengths in centimetres, a common unit of length....
d
Day
A 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...
), a non-SI prefixed unit. Ke literally means 'to etch' or 'to cut', and it is part of the noun Kedu which refers to etched-on markings on measuring devices.
Alongside the ke, the ancient Chinese kept time with double hours (traditional 時辰, simplified 时辰, pinyin shíchen) also known as watches. Because one cannot divide 12 double hours into 100 ke evenly, each ke was subdivided into 60 fen (分; pinyin fēn).
There were various attempts to redefine the ke to 96, 108, or 120 so as to divide evenly into 12 double hours. During the Qing dynasty
Qing Dynasty
The Qing Dynasty was the last dynasty of China, ruling from 1644 to 1912 with a brief, abortive restoration in 1917. It was preceded by the Ming Dynasty and followed by the Republic of China....
around the time of the arrival of Jesuit missionaries, the duration of the ke was finally redefined to one ninety-sixth of a day, or exactly one quarter of a western hour. Today ke is the standard Chinese term to refer to a quarter of an hour. In addition, today's fen is currently used to refer not to 1/60 of a ke but rather 1/60 of an hour, or 1 minute.