diff --git a/src/main/java/eu/m724/wtapi/provider/twilight/impl/approximate/ApproximateTwilightTimeProvider.java b/src/main/java/eu/m724/wtapi/provider/twilight/impl/approximate/ApproximateTwilightTimeProvider.java
index ead0be3..c8ee7ad 100644
--- a/src/main/java/eu/m724/wtapi/provider/twilight/impl/approximate/ApproximateTwilightTimeProvider.java
+++ b/src/main/java/eu/m724/wtapi/provider/twilight/impl/approximate/ApproximateTwilightTimeProvider.java
@@ -27,13 +27,13 @@ public class ApproximateTwilightTimeProvider extends CacheableTwilightTimeProvid
         double n2 = tan(latRad) * tan(declination);
         double hourAngle = acos(n1 - n2);
 
-        double hourAngleDeg = 4 * toDegrees(hourAngle);
+        double longitudeEffect = 4 * toDegrees(hourAngle);
 
         // sunrise = 720 - 4 * (coordinates.longitude + hourAngleDeg) - equationOfTime
         // sunset = 720 - 4 * (coordinates.longitude - hourAngleDeg) - equationOfTime
         double solarNoon = 720 - 4 * coordinates.longitude - equationOfTime;
-        double sunrise = solarNoon - hourAngleDeg;
-        double sunset = solarNoon + hourAngleDeg;
+        double sunrise = solarNoon - longitudeEffect;
+        double sunset = solarNoon + longitudeEffect;
 
         return new Twilight(
                 cache.date(),