Prayer times project

struct Values
{
    public double Val0, Val1;
}
TimeSpan MorningPrayer(byte Month, byte Day, double Longitude, double Latitude)
{
    Values ep = sun(Month, Day, 4, Longitude);
    double zr = ep.Val0,
        delta = ep.Val1,
        ha = loc2hor(108.0, delta, Latitude),
        t = Round(zr - ha, 24);
    ep = sun(Month, Day, t, Longitude);
    zr = ep.Val0;
    delta = ep.Val1;
    ha = loc2hor(108.0, delta, Latitude);
    t = Round(zr - ha, 24);
    return TimeSpan.Parse(hms(t));
}
TimeSpan Sunrise(byte Month, byte Day, double Longitude, double Latitude)
{
    Values ep = sun(Month, Day, 6, Longitude);
    double zr = ep.Val0,
    delta = ep.Val1,
    ha = loc2hor(90.833, delta, Latitude),
    t = Round(zr - ha, 24);
    ep = sun(Month, Day, t, Longitude);
    zr = ep.Val0;
    delta = ep.Val1;
    ha = loc2hor(90.833, delta, Latitude);
    t = Round(zr - ha, 24);
    return TimeSpan.Parse(hms(t));
}
TimeSpan MiddayPrayer(byte Month, byte Day, double Longitude)
{
    Values ep = sun(Month, Day, 12, Longitude);
    ep = sun(Month, Day, ep.Val0, Longitude);
    double zr = ep.Val0;
    return TimeSpan.Parse(hms(zr));
}
TimeSpan Sunset(byte Month, byte Day, double Longitude, double Latitude)
{
    Values ep = sun(Month, Day, 18, Longitude);
    double zr = ep.Val0,
    delta = ep.Val1,
    ha = loc2hor(90.833, delta, Latitude),
    t = Round(zr + ha, 24);
    ep = sun(Month, Day, t, Longitude);
    zr = ep.Val0;
    delta = ep.Val1;
    ha = loc2hor(90.833, delta, Latitude);
    t = Round(zr + ha, 24);
    return TimeSpan.Parse(hms(t));
}
TimeSpan SunsetPrayer(byte Month, byte Day, double Longitude, double Latitude)
{
    Values ep = sun(Month, Day, 18.5, Longitude);
    double zr = ep.Val0,
    delta = ep.Val1,
    ha = loc2hor(94.3, delta, Latitude),
    t = Round(zr + ha, 24);
    ep = sun(Month, Day, t, Longitude);
    zr = ep.Val0;
    delta = ep.Val1;
    ha = loc2hor(94.3, delta, Latitude);
    t = Round(zr + ha, 24);
    return TimeSpan.Parse(hms(t));
}

Values sun(byte m, double d, double h, double lg)
{
    if (m < 7)
        d = 31 * (m - 1) + d + h / 24;
    else
        d = 6 + 30 * (m - 1) + d + h / 24;
    double M = 74.2023 + 0.98560026 * d,
        L = -2.75043 + 0.98564735 * d,
        lst = 8.3162159 + 0.065709824 * Math.Floor(d) + 1.00273791 * 24 * (d % 1) + lg / 15,
        e = 0.0167065,
        omega = 4.85131 - 0.052954 * d,
        ep = 23.4384717 + 0.00256 * cosd(omega),
        ed = 180.0 / Math.PI * e, u = M;
    for (byte i = 1; i < 5; i++)
        u = u - (u - ed * sind(u) - M) / (1 - e * cosd(u));
    double v = 2 * atand(tand(u / 2) * Math.Sqrt((1 + e) / (1 - e))),
        theta = L + v - M - 0.00569 - 0.00479 * sind(omega),
        delta = asind(sind(ep) * sind(theta)),
        alpha = 180.0 / Math.PI * Math.Atan2(cosd(ep) * sind(theta), cosd(theta));
    if (alpha >= 360)
        alpha -= 360;
    double ha = lst - alpha / 15;
    double zr = Round(h - ha, 24);
    Values vlu;
    vlu.Val1 = delta;
    vlu.Val0 = zr;
    return vlu;
}
double sind(double x) { return Math.Sin(Math.PI / 180.0 * x); }
double cosd(double x) { return Math.Cos(Math.PI / 180.0 * x); }
double tand(double x) { return Math.Tan(Math.PI / 180.0 * x); }
double atand(double x) { return Math.Atan(x) * 180.0 / Math.PI; }
double asind(double x) { return Math.Asin(x) * 180.0 / Math.PI; }
double acosd(double x) { return Math.Acos(x) * 180.0 / Math.PI; }
double loc2hor(double z, double d, double p) { return acosd((cosd(z) - sind(d) * sind(p)) / cosd(d) / cosd(p)) / 15; }
double Round(double x, byte a)
{
    double tmp = x % a;
    if (tmp < 0)
        tmp += a;
    return tmp;
}
string hms(double x)
{
    x = Math.Floor(3600 * x);
    double
    h = Math.Floor(x / 3600),
    mp = x - 3600 * h,
    m = Math.Floor(mp / 60),
    s = Math.Floor(mp - 60 * m);
    return h.ToString() + ":" + m.ToString() + ":" + s.ToString();
}

DateTime gregorian = new DateTime(Year, Month, Day);
System.Globalization.PersianCalendar pc = new System.Globalization.PersianCalendar();
            Month = (byte)pc.GetMonth(gregorian);
            Day = (byte)pc.GetDayOfMonth(gregorian);