Option Explicit
Const Pi = 3.14159265358979
Dim Lat, Lng As Double
Function RAD() As Double
RAD = Pi / 180
End Function
Function SunHeight() As Double
SunHeight = (-50# / 60#) * RAD
End Function
Function Sun_Declination(ByVal T As Double) As Double
Sun_Declination = 0.409526325277017 * Sin(1.69060504029192E-02 * (T - 80.0856919827619))
End Function
Function Time_Difference(ByVal Declination As Double) As Double
Time_Difference = 12# * Application.WorksheetFunction.Acos((Sin(SunHeight) - Sin(Lat * RAD) * Sin(Declination))) / (Cos(Lat * RAD) * Cos(Declination)) / Pi
End Function
Function Time_Equation(ByVal T As Double) As Double
Time_Equation = -0.170869921174742 * Sin(3.36997028793971E-02 * T + 0.465419984181394) - 0.129890681040717 * Sin(1.78674832556871E-02 * T - 0.167936777524864)
End Function
Function Sunrise(ByVal T As Double) As Double
Dim SD As Double
SD = Sun_Declination(T)
Sunrise = 12 - Time_Difference(SD) - Time_Equation(T)
End Function
Function SunDown(ByVal T As Double) As Double
Dim SD As Double
SD = Sun_Declination(T)
SunDown = 12 + Time_Difference(SD) - Time_Equation(T)
End Function
Sub Display_Results()
Dim la, ln As String
Dim DiY, hour, td_utc As Double
Dim rise, down, equa, dekl As Double
la = Replace(Worksheets(1).Range("C6"), ".", ",")
ln = Replace(Worksheets(1).Range("C5"), ".", ",")
Lat = CDbl(la)
Lng = CDbl(ln)
DiY = CDbl(Worksheets(1).Range("C7"))
Debug.Print Lng
Debug.Print Lat
rise = Sunrise(DiY)
rise = rise - Lng / 15# + Worksheets(1).Range("C9")
down = SunDown(DiY)
down = down - Lng / 15# + Worksheets(1).Range("C9")
Worksheets(1).Range("C11") = rise
Worksheets(1).Range("C12") = down
Worksheets(1).Range("C13") = Time_Equation(DiY)
Worksheets(1).Range("C14") = Sun_Declination(DiY)
End Sub