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Its value is 0, 1, or 2 at different times of the year. Subtracting it leaves a small positive or negative fractional number of half turns, which is multiplied by 720, the number of minutes (12 hours) that the Earth takes to rotate one half turn relative to the Sun, to get the equation of time.
The stepped reckoner or Leibniz calculator was a mechanical calculator invented by the German mathematician Gottfried Wilhelm Leibniz (started in 1673, when he presented a wooden model to the Royal Society of London [2] and completed in 1694). [1] The name comes from the translation of the German term for its operating mechanism, Staffelwalze ...
A calendrical calculation is a calculation concerning calendar dates. Calendrical calculations can be considered an area of applied mathematics. Some examples of calendrical calculations: Converting a Julian or Gregorian calendar date to its Julian day number and vice versa (see § Julian day number calculation within that article for details ...
The UTC offset is the difference in hours and minutes between Coordinated Universal Time (UTC) and local solar time, at a particular place. This difference is expressed with respect to UTC and is generally shown in the format ± [hh]: [mm], ± [hh] [mm], or ± [hh]. So if the time being described is two hours ahead of UTC (such as in Kigali ...
The cosine of the hour angle (cos(h)) is used to calculate the solar zenith angle. At solar noon, h = 0.000 so cos(h) = 1, and before and after solar noon the cos(± h) term = the same value for morning (negative hour angle) or afternoon (positive hour angle), so that the Sun is at the same altitude in the sky at 11:00AM and 1:00PM solar time. [5]
Pascal's calculator (also known as the arithmetic machine or Pascaline) is a mechanical calculator invented by Blaise Pascal in 1642. Pascal was led to develop a calculator by the laborious arithmetical calculations required by his father's work as the supervisor of taxes in Rouen. [2] He designed the machine to add and subtract two numbers ...
The daytime canonical hours of the Catholic Church take their names from the Roman clock: the prime, terce, sext and none occur during the first (prīma) = 6 am, third (tertia) = 9 am, sixth (sexta) = 12 pm, and ninth (nōna) = 3 pm, hours of the day. The English term noon is also derived from the ninth hour. This was a period of prayer ...
The C date and time operations are defined in the time.h header file (ctime header in C++). returns the current time of the system as a time_t value, number of seconds, (which is usually time since an epoch, typically the Unix epoch). The value of the epoch is operating system dependent; 1900 and 1970 are often used. See RFC 868.