Editing Water clock (section)

===Persia===
[[File:Ancient water clock used in qanat of gonabad 2500 years ago.JPG|thumb|Ancient Persian clock]]

The use of water clocks in [[Greater Iran]], especially in the desert areas such as [[Yazd]], [[Isfahan]], [[Zibad]], and [[Gonabad]], dates back to 500 BC.<ref>{{cite web |first=G.H. |last=Rahimi |work=Tehran university science magazine |url=https://jihs.ut.ac.ir/article_69801_e14a6b2d0d61cd4df20e24ffd5b216a4.pdf |title=Water Sharing Management in Ancient Iran, with Special Reference to Pangān (cup) in Iran}}
</ref> Later, they were also used to determine the exact holy days of pre-Islamic religions such as [[Nowruz]] ([[March equinox]]), [[Mehregan]] ([[September equinox]]), [[Tirgan]] ([[summer solstice]]) and [[Yaldā Night]] ([[winter solstice]]) – the shortest, longest, and equal-length days and nights of the years. The water clocks, called ''pengan'' (and later ''fenjan'') used were one of the most practical ancient tools for timing the yearly calendar.<ref name=Qanat>{{cite web|url=http://www.aftabir.com/articles/view/science_education/technical/c3c1183387267p1.php|title=Conference of Qanat in Iran – water clock in Persia 1383|website=www.aftabir.com|language=fa}}</ref><ref name="japan.mfa.gov.ir">{{Cite web|url=https://japan.mfa.gov.ir/en/newsview/536035|title=Qanat is cultural and social and scientific heritage in Iran}}</ref> The water clock was the most accurate and commonly used timekeeping device for calculating the amount or the time that a farmer must take water from a [[qanat]] or well for irrigation until more accurate current clocks replaced it.<ref>{{cite web|url=http://parssea.org/?p=2734|title= Water clock or Pengan in Iran, National conference 2004 Gonabad  |website=parssea.org|archive-url= https://web.archive.org/web/20170610061516/http://parssea.org/?p=2734 |archive-date= 2017-06-10 }}</ref><ref>{{cite web|url=http://vista.ir/article/265134|title= Qanat iscultural and social and scientific heritage in Iran |last=vista.ir}}</ref>

Persian water clocks were a practical, useful, and necessary tool for the qanat's shareholders to calculate the length of time they could divert water to their farms or gardens. The qanat was the only water source for agriculture and irrigation in arid area so a just and fair water distribution was very important. Therefore, a very fair and clever old person was elected to be the manager of the water clock or ''mir āb'', and at least two full-time managers were needed to control and observe the number of hours and announce the exact time of the days and nights from sunrise to sunset because shareholders usually divided between day and night owners.<ref name="amordadnews.com">{{cite news|url=http://amordadnews.com/neveshtehNamyesh.aspx?NId=6010|title=water clock in persia|work=amordadnews.com|url-status=dead|archive-url=https://web.archive.org/web/20140429163019/http://amordadnews.com/neveshtehNamyesh.aspx?NId=6010|archive-date=2014-04-29}}</ref>

The Persian water clock consisted of a large pot full of water and a bowl with a small hole in the center. When the bowl became full of water, it would sink into the pot, and the manager would empty the bowl and again put it on the top of the water in the pot. He would record the number of times the bowl sank by putting small stones into a jar.<ref name="amordadnews.com"/> The place where the clock was situated and its managers were collectively known as the ''khane pengān''. Usually this would be the top floor of a public house, with west- and east-facing windows to show the time of sunset and sunrise. The [[Zibad]] water clock was in use until 1965,<ref name="japan.mfa.gov.ir"/> when it was replaced by modern clocks.<ref name=Qanat/>