diff --git a/lib/taskana-core/src/main/java/pro/taskana/impl/DaysToWorkingDaysConverter.java b/lib/taskana-core/src/main/java/pro/taskana/impl/DaysToWorkingDaysConverter.java
index cf259583a..c352fd316 100644
--- a/lib/taskana-core/src/main/java/pro/taskana/impl/DaysToWorkingDaysConverter.java
+++ b/lib/taskana-core/src/main/java/pro/taskana/impl/DaysToWorkingDaysConverter.java
@@ -182,7 +182,7 @@ public final class DaysToWorkingDaysConverter {
     }
 
     public long convertWorkingDaysToDays(Instant startTime, long numberOfDays) {
-        int direction = numberOfDays > 0 ? 1 : -1;
+        int direction = numberOfDays >= 0 ? 1 : -1;
         long limit = Math.abs(numberOfDays);
         return LongStream.iterate(0, i -> i + direction)
             .filter(day -> isWorkingDay(day, startTime))
@@ -293,12 +293,12 @@ public final class DaysToWorkingDaysConverter {
 
     @Override
     public String toString() {
-        return "DaysToWorkingDaysConverter [instance= " + instance
-            + ", positiveDaysToWorkingDays= " + positiveDaysToWorkingDays
-            + ", negativeDaysToWorkingDays= " + negativeDaysToWorkingDays
-            + ", dateCreated= " + dateCreated + ", easterSunday= " + easterSunday
-            + ", germanHolidaysEnabled= " + germanHolidaysEnabled
-            + ", customHolidays= " + LoggerUtils.setToString(customHolidays) + "]";
+        return "DaysToWorkingDaysConverter{"
+            + "positiveDaysToWorkingDays=" + positiveDaysToWorkingDays
+            + ", negativeDaysToWorkingDays=" + negativeDaysToWorkingDays
+            + ", dateCreated=" + dateCreated
+            + ", easterSunday=" + easterSunday
+            + '}';
     }
 
     /**
diff --git a/lib/taskana-core/src/test/java/acceptance/task/CreateTaskAccTest.java b/lib/taskana-core/src/test/java/acceptance/task/CreateTaskAccTest.java
index 4a1b05709..0e2fe172d 100644
--- a/lib/taskana-core/src/test/java/acceptance/task/CreateTaskAccTest.java
+++ b/lib/taskana-core/src/test/java/acceptance/task/CreateTaskAccTest.java
@@ -162,10 +162,13 @@ class CreateTaskAccTest extends AbstractAccTest {
         newTask.setPrimaryObjRef(createObjectReference("COMPANY_A", "SYSTEM_A", "INSTANCE_A", "VNR", "1234567"));
         newTask.setOwner("user_1_1");
 
-        newTask.setPlanned(instantPlanned);
+        Optional<DaysToWorkingDaysConverter> converter = DaysToWorkingDaysConverter.getLastCreatedInstance();
+        //TODO: this is a temporal bug fix because we did not define what happens when a task is planned on the weekend.
+        long i = converter.get().convertWorkingDaysToDays(instantPlanned, 0);
+        newTask.setPlanned(instantPlanned.plus(Duration.ofDays(i)));
         //due date according to service level
-        Instant shouldBeDueDate = DaysToWorkingDaysConverter.getLastCreatedInstance()
-            .map(converter -> converter.convertWorkingDaysToDays(newTask.getPlanned(), serviceLevelDays))
+        Instant shouldBeDueDate = converter
+            .map(c -> c.convertWorkingDaysToDays(newTask.getPlanned(), serviceLevelDays))
             .map(
                 calendarDays -> newTask.getPlanned().plus(Duration.ofDays(calendarDays))).orElseThrow(
                 RuntimeException::new);