Editing Hour (section)

===East Asia===
{{main|Traditional Chinese timekeeping}}
[[File:Clock Tower from Su Song's Book.JPG|thumb|right|200px|A Chinese diagram from [[Su Song]]'s AD{{nbsp}}1092 ''Xinyi Xiangfa Yao'' illustrating his clocktower at [[Kaifeng]].]]
[[File:Beijing_2006_1-14.jpg|thumb|right|200px|A reconstruction of another kind of Chinese [[Water clock|clepsydra]] in [[Beijing]]'s [[Beijing Drum Tower|Drum Tower]]]]

[[Ancient China]] divided its day into 100 "marks"{{sfnp|Stephenson|1997}}{{sfnp|Steele|2000}} {{nowrap|([[Chinese language|Chinese]]: {{lang|zh|{{linktext|刻}}}},}} {{nowrap|<small>[[Old Chinese|oc]]</small> [[linguistic reconstruction|*]]''kʰək'',{{sfnp|Baxter & al.|2014}}}} {{nowrap|<small>[[pinyin|p]]</small> ''kè'')}} running from midnight to midnight.{{sfnp|Sōma & al.|2004|p=887}} The system is said to have been used since [[prehistoric China|remote antiquity]],{{sfnp|Sōma & al.|2004|p=887}} credited to the legendary [[Yellow Emperor]],{{sfnp|Petersen|1992|p=129}} but is first attested in [[Western Han|Han]]-era [[water clock]]s{{sfnp|Petersen|1992|p=125}} and in the [[Book of Han|2nd-century history]] of that [[list of Chinese dynasties|dynasty]].{{sfnp|Sōma & al.|2004|p=889}} It was measured with sundials{{sfnp|Stephenson & al.|2002|pp=15–16}} and [[water clock]]s.{{efn|According to the 2nd-century ''[[Shuowen Jiezi]]'', "A water clock holds the water in a copper pot and notes the marks [''kè''] by a rule. There are 100 marks which represent the day".}} Into the [[Eastern Han]], the Chinese measured their day schematically, adding the 20-''ke'' difference between the solstices evenly throughout the year, one every nine days.{{sfnp|Petersen|1992|p=125}} During the night, time was more commonly reckoned during the night by the "watches" {{nowrap|([[Chinese language|Chinese]]: {{lang|zh|{{linktext|更}}}},}} {{nowrap|<small>[[Old Chinese|oc]]</small> [[linguistic reconstruction|*]]''kæŋ'',{{sfnp|Baxter & al.|2014}}}} {{nowrap|<small>[[pinyin|p]]</small> ''gēng'')}} of the guard, which were reckoned as a fifth of the time from [[sunset]] to [[sunrise]].{{sfnp|Stephenson|1997}}{{sfnp|Sōma & al.|2004|p=888}}

[[Imperial China]] continued to use ''ke'' and ''geng'' but also began to divide the day into 12 "double hours" {{nowrap|(<small>[[traditional characters|t]]</small> {{lang|zh|{{linktext|時}}}},}} {{nowrap|<small>[[simplified characters|s]]</small> {{lang|zh|{{linktext|时}}}},}} {{nowrap|<small>[[Old Chinese|oc]]</small> [[linguistic reconstruction|*]]''də'',{{sfnp|Baxter & al.|2014}}}} {{nowrap|<small>[[pinyin|p]]</small> ''shí'',}} {{nowrap|{{abbr|lit.|literally}} "time[s]")}} named after the [[earthly branches]] and sometimes also known by the name of the corresponding animal of the [[Chinese zodiac]].{{sfnp|Sōma & al.|2004|p=904}} The first ''shi'' originally ran from 11{{nbsp}}pm to 1{{nbsp}}am but was reckoned as starting at midnight by the time of the [[History of Song (Yuan dynasty)|History of Song]], compiled during the early [[Yuan Dynasty|Yuan]].{{sfnp|Sōma & al.|2004|p=896}} These apparently began to be used during the [[Eastern Han]] that preceded the [[Three Kingdoms]] era, but the sections that would have covered them are missing from their official histories; they first appear in official use in the [[Tang dynasty|Tang]]-era [[Book of Sui]].{{sfnp|Sōma & al.|2004|p=889}} Variations of all these units were subsequently adopted by [[ancient Japan|Japan]]{{sfnp|Sōma & al.|2004|p=888}} and the other countries of the [[Sinosphere]].

The 12 ''shi'' supposedly began to be divided into 24 hours under the [[Tang dynasty|Tang]],{{sfnp|Sōma & al.|2004|p=888}} although they are first attested in the [[Ming]]-era [[Book of Yuan]].{{sfnp|Sōma & al.|2004|p=887}} In that work, the hours were known by the same [[earthly branches]] as the ''shi'', with the first half noted as its "starting" and the second as "completed" or "proper" ''shi''.{{sfnp|Sōma & al.|2004|p=887}} In modern China, these are instead simply numbered and described as "little ''shi''". The modern ''ke'' is now used to count quarter-hours, rather than a separate unit.

As with the Egyptian night and daytime hours, the division of the day into 12 ''shi'' has been credited to the example set by the rough number of lunar cycles in a solar year,<ref>{{Cite book|chapter-url=https://digitalis.uc.pt/pt-pt/livro/timeless_legacy_calendars_ancient_egypt|chapter=A Timeless Legacy: the Calendars of Ancient Egypt|last=Canhão|first=Telo Ferreira|date=2013|publisher=Edições Afrontamento|isbn=9789892609669|location=Porto|doi=10.14195/978-989-26-0966-9_20|title=Alexandrea ad Aegyptvm: The legacy of multiculturalismo in antiquity|pages=283–301}}</ref> although the 12-year [[Jupiter|Jovian]] orbital cycle was more important to [[Chinese zodiac|traditional Chinese]]<ref>{{citation |last=Zai |first=J. |title=Taoism and Science |publisher=Ultravisum |date=2015 }}</ref> and Babylonian reckoning of the zodiac.{{sfnp|Rogers|1998|pp=9–28}}{{efn|The late classical Indians also began to reckon [[Samvatsara|years based on the Jovian cycle]], but this was much later than their lunar calendar and initially named after it.{{sfnp|Sewell|1924|p=[https://books.google.com/books?id=LQffS160KxEC&pg=PR12 xii]}}}}