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Equation of time 9/9 https://en.wikipedia.org/wiki/Equation_of_time reference science, encyclopedia 2026-05-05T11:12:39.793727+00:00 kb-cron

The value of B in the above calculation is an accurate value for the Sun's ecliptic longitude (shifted by 90°), so the solar declination δ becomes readily available:

    δ
    =
    
    arcsin
    
    
      (
      
        sin
        
        
          23.44
          
            ∘
          
        
        ⋅
        cos
        
        B
      
      )
    
  

{\displaystyle \delta =-\arcsin \left(\sin 23.44^{\circ }\cdot \cos B\right)}

which is accurate to within a fraction of a degree.

== See also == Azimuth Horizontal angle from north or other reference cardinal direction Milankovitch cycles Global climate cycles

== Notes ==

== References ==

== External links ==

NOAA Solar Calculator "USNO data services". Archived from the original on 29 May 2014. (include rise/set/transit times of the Sun and other celestial objects) The equation of time described on the Royal Greenwich Observatory web site The Equation of Time and the Analemma, by Kieron Taylor An article by Brian Tung containing a link to a C program using a more accurate formula than most (particularly at high inclinations and eccentricities). The program can calculate solar declination, Equation of Time, or Analemma Doing calculations using Ptolemy's geocentric planetary models with a discussion of his E.T. graph Equation of Time Longcase Clock by John Topping C.1720 The equation of time correction-table A page describing how to correct a clock to a sundial Solar tempometer: Calculate your solar time, including the equation of time