diff --git a/src/definition/AtmosphereDefinition.cpp b/src/definition/AtmosphereDefinition.cpp
index 265f632..ac0e5da 100644
--- a/src/definition/AtmosphereDefinition.cpp
+++ b/src/definition/AtmosphereDefinition.cpp
@@ -74,7 +74,7 @@ void AtmosphereDefinition::setDayTime(double value) {
 }
 
 void AtmosphereDefinition::setDayTime(int hour, int minute, int second) {
-    setDayTime(to_double(hour) / 24.0 + to_double(minute) / 1440.0 + to_double(second) / 86400.0);
+    setDayTime(to_double(hour) / 24.0 + to_double(minute) / 1440.0 + (to_double(second) + 0.1) / 86400.0);
 }
 
 double AtmosphereDefinition::getDaytime() const {
diff --git a/src/tests/AtmosphereDefinition_Test.cpp b/src/tests/AtmosphereDefinition_Test.cpp
index 5d57f4e..182f3e4 100644
--- a/src/tests/AtmosphereDefinition_Test.cpp
+++ b/src/tests/AtmosphereDefinition_Test.cpp
@@ -11,6 +11,11 @@ static void check_daytime(const AtmosphereDefinition &atmo, int expected_hour, i
     EXPECT_EQ(expected_second, second);
 }
 
+static void check_auto_daytime(AtmosphereDefinition &atmo, int hour, int minute=0, int second=0) {
+    atmo.setDayTime(hour, minute, second);
+    check_daytime(atmo, hour, minute, second);
+}
+
 TEST(AtmosphereDefinition, setDayTime) {
     AtmosphereDefinition atmo(NULL);
 
@@ -34,4 +39,8 @@ TEST(AtmosphereDefinition, setDayTime) {
 
     atmo.setDayTime(1.5);
     check_daytime(atmo, 12);
+
+    check_auto_daytime(atmo, 15);
+    check_auto_daytime(atmo, 15, 12);
+    check_auto_daytime(atmo, 15, 18, 7);
 }