func EclipticLongitude(solarAnomaly, equationOfCenter, d float64) float64 {
	return math.Mod(solarAnomaly+equationOfCenter+180+ArgumentOfPerihelion(d), 360)
}
EclipticLongitude calculates the angular distance of the earth along the
ecliptic.
package sunrise
import (
	"math"
)