/// <summary>
/// Compute equation of time for given julian date.
/// </summary>
private static double ComputeEquationOfTime(double julianDate)
{
var epochDaysFraction = ComputeEpochDaysFraction(julianDate);
var sunMeanAnomaly = ComputeSunMeanAnomaly(epochDaysFraction);
var sunMeanLongitude = ComputeSunMeanLongitude(epochDaysFraction);
var sunEclipticLongitude = ComputeSunEclipticLongitude(sunMeanLongitude, sunMeanAnomaly);
var eclipticMeanObliquity = ComputeEclipticMeanObliquity(epochDaysFraction);
var sunRightAscension = ComputeSunRightAscension(eclipticMeanObliquity, sunEclipticLongitude);
return((sunMeanLongitude / 15.0) - DateTimeMath.FixHour(sunRightAscension));
}
/// <summary>
/// Compute mid day hours for given julian date and time fraction.
/// </summary>
/// <param name="julianDate">
/// Julian date of mid day hours to be computed.
/// </param>
/// <param name="timeFraction">
/// Time fraction of the day of mid day hours to be computed.
/// </param>
/// <returns>
/// Mid day hours for given julian date and time fraction.
/// </returns>
internal static double ComputeMidDay(double julianDate, double timeFraction)
{
var equationOfTime = ComputeEquationOfTime(julianDate + timeFraction);
return(DateTimeMath.FixHour(12.0 - equationOfTime));
}