diff --git a/pom.xml b/pom.xml
index 03a117f..5c7e521 100644
--- a/pom.xml
+++ b/pom.xml
@@ -66,6 +66,12 @@
       <version>1.2</version>
     </dependency>
 
+    <dependency>
+      <groupId>org.springframework.boot</groupId>
+      <artifactId>spring-boot-starter-test</artifactId>
+      <scope>test</scope>
+    </dependency>
+
   </dependencies>
   <build>
     <plugins>
diff --git a/src/main/java/de/ph87/homeautomation/Config.java b/src/main/java/de/ph87/homeautomation/Config.java
index 0cd7502..959b847 100644
--- a/src/main/java/de/ph87/homeautomation/Config.java
+++ b/src/main/java/de/ph87/homeautomation/Config.java
@@ -13,8 +13,6 @@ public class Config {
 
   private double longitude = 6.9645334;
 
-  private String timezone = "Europe/Berlin";
-
   private boolean insertDemoData = false;
 
 }
diff --git a/src/main/java/de/ph87/homeautomation/schedule/ScheduleCalculator.java b/src/main/java/de/ph87/homeautomation/schedule/ScheduleCalculator.java
index 3a429f1..5d30a36 100644
--- a/src/main/java/de/ph87/homeautomation/schedule/ScheduleCalculator.java
+++ b/src/main/java/de/ph87/homeautomation/schedule/ScheduleCalculator.java
@@ -11,6 +11,8 @@ import org.springframework.context.event.EventListener;
 import org.springframework.stereotype.Service;
 import org.springframework.transaction.annotation.Transactional;
 
+import java.time.LocalDate;
+import java.time.ZoneId;
 import java.time.ZonedDateTime;
 import java.util.Comparator;
 import java.util.Optional;
@@ -55,12 +57,12 @@ public class ScheduleCalculator {
       entry.setNextClearTimestamp(null);
       return;
     }
-    ZonedDateTime midnight = now.withHour(0).withMinute(0).withSecond(0).withNano(0);
-    ZonedDateTime next = calculateEntryForDay(entry, midnight);
+    LocalDate day = now.toLocalDate();
+    ZonedDateTime next = calculateEntryForDay(entry, day);
     while (next != null && (!next.isAfter(now) || !isAfterLast(entry, next) || !isWeekdayEnabled(entry, next))) {
       log.debug("  -- skipping: next={}", next);
-      midnight = midnight.plusDays(1);
-      next = calculateEntryForDay(entry, midnight);
+      day = day.plusDays(1);
+      next = calculateEntryForDay(entry, day);
     }
     log.debug("  => {}", next);
     entry.setNextClearTimestamp(next);
@@ -70,14 +72,14 @@ public class ScheduleCalculator {
     return entry.getLastClearTimestamp() == null || next.isAfter(entry.getLastClearTimestamp());
   }
 
-  private ZonedDateTime calculateEntryForDay(final ScheduleEntry entry, final ZonedDateTime midnight) {
+  private ZonedDateTime calculateEntryForDay(final ScheduleEntry entry, final LocalDate day) {
     switch (entry.getType()) {
       case TIME:
-        return midnight.withHour(entry.getHour()).withMinute(entry.getMinute()).withSecond(entry.getSecond());
+        return day.atStartOfDay().atZone(ZoneId.systemDefault()).withHour(entry.getHour()).withMinute(entry.getMinute()).withSecond(entry.getSecond());
       case SUNRISE:
       case SUNSET:
         final boolean sunrise = entry.getType() == ScheduleEntryType.SUNRISE;
-        return astroCalculator.forDay(midnight, sunrise, entry.getZenith());
+        return astroCalculator.forDay(day, sunrise, entry.getZenith()).withLaterOffsetAtOverlap();
       default:
         log.error("AstroEvent not implemented: {}", entry.getType());
         break;
diff --git a/src/main/java/de/ph87/homeautomation/schedule/astro/AstroCalculator.java b/src/main/java/de/ph87/homeautomation/schedule/astro/AstroCalculator.java
index 5bef5cb..b88714a 100644
--- a/src/main/java/de/ph87/homeautomation/schedule/astro/AstroCalculator.java
+++ b/src/main/java/de/ph87/homeautomation/schedule/astro/AstroCalculator.java
@@ -8,10 +8,12 @@ import lombok.RequiredArgsConstructor;
 import org.springframework.stereotype.Service;
 
 import java.time.Instant;
+import java.time.LocalDate;
+import java.time.ZoneId;
 import java.time.ZonedDateTime;
-import java.time.temporal.ChronoUnit;
 import java.util.Calendar;
 import java.util.GregorianCalendar;
+import java.util.TimeZone;
 
 @Service
 @RequiredArgsConstructor
@@ -19,25 +21,15 @@ public class AstroCalculator {
 
   private final Config config;
 
-  public ZonedDateTime next(final ZonedDateTime now, final boolean sunrise, final double zenith) {
-    ZonedDateTime day = now.truncatedTo(ChronoUnit.DAYS);
-    ZonedDateTime next;
-    do {
-      next = forDay(day, sunrise, zenith);
-      day = day.plusDays(1);
-    } while (next != null && !next.isAfter(now));
-    return next;
-  }
-
-  public ZonedDateTime forDay(final ZonedDateTime midnight, final boolean sunrise, final double zenith) {
+  public ZonedDateTime forDay(final LocalDate day, final boolean sunrise, final double zenith) {
     final Location location = new Location(config.getLatitude(), config.getLongitude());
-    final SolarEventCalculator calculator = new SolarEventCalculator(location, config.getTimezone());
-    final Calendar calendar = GregorianCalendar.from(midnight);
+    final SolarEventCalculator calculator = new SolarEventCalculator(location, TimeZone.getTimeZone("UTC"));
+    final Calendar calendar = GregorianCalendar.from(day.atStartOfDay(ZoneId.of("UTC")));
     final Calendar nextCalendar = forDay(calculator, sunrise, new Zenith(zenith), calendar);
     if (nextCalendar == null) {
       return null;
     }
-    return ZonedDateTime.ofInstant(Instant.ofEpochMilli(nextCalendar.getTimeInMillis()), midnight.getZone());
+    return ZonedDateTime.ofInstant(Instant.ofEpochMilli(nextCalendar.getTimeInMillis()), ZoneId.systemDefault());
   }
 
   private Calendar forDay(final SolarEventCalculator calculator, final boolean sunrise, final Zenith solarZenith, final Calendar calendar) {
diff --git a/src/test/java/de/ph87/homeautomation/schedule/ScheduleCalculatorDaylightSavingTimeTransitionTest.java b/src/test/java/de/ph87/homeautomation/schedule/ScheduleCalculatorDaylightSavingTimeTransitionTest.java
new file mode 100644
index 0000000..bbfbbe1
--- /dev/null
+++ b/src/test/java/de/ph87/homeautomation/schedule/ScheduleCalculatorDaylightSavingTimeTransitionTest.java
@@ -0,0 +1,70 @@
+package de.ph87.homeautomation.schedule;
+
+import de.ph87.homeautomation.Config;
+import de.ph87.homeautomation.schedule.astro.AstroCalculator;
+import lombok.extern.slf4j.Slf4j;
+import org.junit.jupiter.api.Test;
+
+import java.time.ZoneId;
+import java.time.ZonedDateTime;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+@Slf4j
+class ScheduleCalculatorDaylightSavingTimeTransitionTest {
+
+  private static final ZonedDateTime DAY_OF_DST_SET_BACK = ZonedDateTime.of(2024, 10, 27, 0, 0, 0, 0, ZoneId.of("Europe/Berlin"));
+
+  private static final AstroCalculator astroCalculator = new AstroCalculator(new Config());
+
+  @Test
+  void withHour() {
+    final ZonedDateTime morning = DAY_OF_DST_SET_BACK.withHour(6);
+    assertEquals(6, morning.getHour());
+    assertEquals(0, morning.getMinute());
+    assertEquals(0, morning.getSecond());
+    assertEquals(0, morning.getNano());
+    assertEquals(3600, morning.getOffset().getTotalSeconds());
+  }
+
+  @Test
+  void sunrise_dstSetBack() {
+    final ZonedDateTime morning = astroCalculator.forDay(DAY_OF_DST_SET_BACK.toLocalDate(), true, 90);
+    assertEquals(7, morning.getHour());
+    assertEquals(19, morning.getMinute());
+    assertEquals(0, morning.getSecond());
+    assertEquals(0, morning.getNano());
+    assertEquals(3600, morning.getOffset().getTotalSeconds());
+  }
+
+  @Test
+  void sunset_dstSetBack() {
+    final ZonedDateTime morning = astroCalculator.forDay(DAY_OF_DST_SET_BACK.toLocalDate(), false, 90);
+    assertEquals(17, morning.getHour());
+    assertEquals(13, morning.getMinute());
+    assertEquals(0, morning.getSecond());
+    assertEquals(0, morning.getNano());
+    assertEquals(3600, morning.getOffset().getTotalSeconds());
+  }
+
+  @Test
+  void sunrise_noDstChange() {
+    final ZonedDateTime morning = astroCalculator.forDay(DAY_OF_DST_SET_BACK.minusDays(1).toLocalDate(), true, 90);
+    assertEquals(8, morning.getHour());
+    assertEquals(17, morning.getMinute());
+    assertEquals(0, morning.getSecond());
+    assertEquals(0, morning.getNano());
+    assertEquals(7200, morning.getOffset().getTotalSeconds());
+  }
+
+  @Test
+  void sunset_noDstChange() {
+    final ZonedDateTime morning = astroCalculator.forDay(DAY_OF_DST_SET_BACK.minusDays(1).toLocalDate(), false, 90);
+    assertEquals(18, morning.getHour());
+    assertEquals(14, morning.getMinute());
+    assertEquals(0, morning.getSecond());
+    assertEquals(0, morning.getNano());
+    assertEquals(7200, morning.getOffset().getTotalSeconds());
+  }
+
+}
\ No newline at end of file