Shareholders
The Persian were using water clocks in 328 BC to ensure a just and exact distribution of water from qanats to their shareholders for agricultural irrigation. The use of water clocks in Iran, especially in Zeebad, dates back to 500BC. Later they were also used to determine the exact holy days of pre-Islamic religions, such as the Nowruz, Chelah, or Yaldā - the shortest, longest, and equal-length days and nights of the years. The water clocks used in Iran were one of the most practical ancient tools for timing the yearly calendar.. Water clocks, or Fenjaan, in Persia reached a level of accuracy comparable to today's standards of timekeeping. The fenjaan 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 it was replaced by more accurate current clock. Persian water clocks were a practical and useful tool for the qanat's shareholders to calculate the length of time they could divert water to their farm. The qanat was the only water source for agriculture and irrigation 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, and at least two full-time managers were needed to control and observe the number of fenjaans and announce the exact time during the days and nights.
The fenjaan was a big pot full of water and a bowl with small hole in the center. When the bowl become 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.
The place where the clock was situated, and its managers, were collectively known as khaneh fenjaan. 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. There was also another time-keeping tool named a staryab or astrolabe, but it was mostly used for superstitious beliefs and was not practical for use as a farmers' calendar. The Zeebad Gonabad water clock was in used until 1965 when it was substituted by modern clocks. .
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