diff --git a/lib/taskana-core/src/main/java/pro/taskana/impl/DailyEntryExitReportBuilderImpl.java b/lib/taskana-core/src/main/java/pro/taskana/impl/DailyEntryExitReportBuilderImpl.java
index 3259644c4..ab7f6b9d3 100644
--- a/lib/taskana-core/src/main/java/pro/taskana/impl/DailyEntryExitReportBuilderImpl.java
+++ b/lib/taskana-core/src/main/java/pro/taskana/impl/DailyEntryExitReportBuilderImpl.java
@@ -46,11 +46,9 @@ public class DailyEntryExitReportBuilderImpl extends
         return this;
     }
 
-    // since this method is not documented I have no idea what the proper groupedBy should be,
-    // thus this method is not supported on this builder.
     @Override
     public List<String> listTaskIdsForSelectedItems(List<SelectedItem> selectedItems) {
-        throw new UnsupportedOperationException("");
+        throw new UnsupportedOperationException();
     }
 
     @Override
diff --git a/lib/taskana-core/src/main/java/pro/taskana/impl/TimeIntervalReportBuilderImpl.java b/lib/taskana-core/src/main/java/pro/taskana/impl/TimeIntervalReportBuilderImpl.java
index 143f582d1..60443b1ff 100644
--- a/lib/taskana-core/src/main/java/pro/taskana/impl/TimeIntervalReportBuilderImpl.java
+++ b/lib/taskana-core/src/main/java/pro/taskana/impl/TimeIntervalReportBuilderImpl.java
@@ -92,7 +92,7 @@ abstract class TimeIntervalReportBuilderImpl<B extends TimeIntervalReportBuilder
 
     @Override
     public B excludedClassificationIdIn(List<String> excludedClassificationIds) {
-        this.excludedClassificationIds = excludedClassificationIds;
+        this.excludedClassificationIds = new ArrayList<>(excludedClassificationIds);
         return _this();
     }
 
diff --git a/lib/taskana-core/src/test/java/acceptance/report/GetTaskIdsOfClassificationReportAccTest.java b/lib/taskana-core/src/test/java/acceptance/report/GetTaskIdsOfClassificationReportAccTest.java
index ee96cb57f..4bcd20221 100644
--- a/lib/taskana-core/src/test/java/acceptance/report/GetTaskIdsOfClassificationReportAccTest.java
+++ b/lib/taskana-core/src/test/java/acceptance/report/GetTaskIdsOfClassificationReportAccTest.java
@@ -27,8 +27,6 @@ public class GetTaskIdsOfClassificationReportAccTest extends AbstractReportAccTe
     public void testRoleCheck() throws InvalidArgumentException, NotAuthorizedException {
         TaskMonitorService taskMonitorService = taskanaEngine.getTaskMonitorService();
 
-        List<TimeIntervalColumnHeader> columnHeaders = getListOfColumnHeaders();
-
         List<SelectedItem> selectedItems = new ArrayList<>();
 
         SelectedItem s1 = new SelectedItem();
diff --git a/lib/taskana-core/src/test/java/acceptance/report/GetDailyEntryExitReportAccTest.java b/lib/taskana-core/src/test/java/acceptance/report/ProvideDailyEntryExitReportAccTest.java
similarity index 97%
rename from lib/taskana-core/src/test/java/acceptance/report/GetDailyEntryExitReportAccTest.java
rename to lib/taskana-core/src/test/java/acceptance/report/ProvideDailyEntryExitReportAccTest.java
index f6130cc72..fbc8d2dbb 100644
--- a/lib/taskana-core/src/test/java/acceptance/report/GetDailyEntryExitReportAccTest.java
+++ b/lib/taskana-core/src/test/java/acceptance/report/ProvideDailyEntryExitReportAccTest.java
@@ -14,7 +14,6 @@ import org.junit.Test;
 import org.junit.runner.RunWith;
 
 import pro.taskana.TaskMonitorService;
-import pro.taskana.TaskanaEngine;
 import pro.taskana.impl.report.header.TimeIntervalColumnHeader;
 import pro.taskana.impl.report.item.DailyEntryExitQueryItem;
 import pro.taskana.impl.report.row.DailyEntryExitRow;
@@ -27,7 +26,7 @@ import pro.taskana.security.WithAccessId;
  * Test class for {@link pro.taskana.report.DailyEntryExitReport}.
  */
 @RunWith(JAASRunner.class)
-public class GetDailyEntryExitReportAccTest extends AbstractReportAccTest {
+public class ProvideDailyEntryExitReportAccTest extends AbstractReportAccTest {
 
     /**
      * This test covers every insert operation of the DailyEntryExitReport.
@@ -41,7 +40,6 @@ public class GetDailyEntryExitReportAccTest extends AbstractReportAccTest {
     @WithAccessId(userName = "monitor")
     @Test
     public void testProperInsertionOfQueryItems() throws Exception {
-        taskanaEngine.setConnectionManagementMode(TaskanaEngine.ConnectionManagementMode.AUTOCOMMIT);
         TaskMonitorService mapper = taskanaEngine.getTaskMonitorService();
 
         //last 14 days. Today excluded.
diff --git a/lib/taskana-core/src/test/java/pro/taskana/impl/ClassificationServiceImplTest.java b/lib/taskana-core/src/test/java/pro/taskana/impl/ClassificationServiceImplTest.java
index 5a6cb0b2d..c5a25241b 100644
--- a/lib/taskana-core/src/test/java/pro/taskana/impl/ClassificationServiceImplTest.java
+++ b/lib/taskana-core/src/test/java/pro/taskana/impl/ClassificationServiceImplTest.java
@@ -7,6 +7,7 @@ import static org.mockito.Mockito.doReturn;
 import static org.mockito.Mockito.verifyNoMoreInteractions;
 
 import java.time.Instant;
+import java.time.temporal.ChronoUnit;
 import java.util.List;
 
 import org.apache.ibatis.session.SqlSession;
@@ -36,11 +37,6 @@ import pro.taskana.mappings.JobMapper;
 @RunWith(MockitoJUnitRunner.class)
 public class ClassificationServiceImplTest {
 
-    // This is important. Since ClassificationService.createClassification() uses an Instant for the time
-    // and thus the UTC time zone. e.g. LocalDate uses the system timezone. This may lead to issues when the day differs
-    // between those timezones.
-    private final String todaysDate = Instant.now().toString().substring(0, 10);
-
     @Spy
     @InjectMocks
     private ClassificationServiceImpl cutSpy;