diff --git a/src/main/java/ch/zhaw/gartenverwaltung/Main.java b/src/main/java/ch/zhaw/gartenverwaltung/Main.java
index d31860d..f757926 100644
--- a/src/main/java/ch/zhaw/gartenverwaltung/Main.java
+++ b/src/main/java/ch/zhaw/gartenverwaltung/Main.java
@@ -22,13 +22,14 @@ public class Main extends Application {
         AppLoader appLoader = new AppLoader();
 
         backgroundTasks = new BackgroundTasks((TaskList) appLoader.getAppDependency(TaskList.class),(CropList) appLoader.getAppDependency(CropList.class), (PlantList) appLoader.getAppDependency(PlantList.class));
-        // TODO reduce period
-        backGroundTaskTimer.scheduleAtFixedRate(backgroundTasks, 0, 1000);
 
         appLoader.loadSceneToStage("MainFXML.fxml", stage);
 
         stage.setTitle("Gartenverwaltung");
         stage.show();
+
+        backGroundTaskTimer.scheduleAtFixedRate(backgroundTasks, 0, 60000);
+
     }
 
     @Override
diff --git a/src/main/java/ch/zhaw/gartenverwaltung/io/JsonTaskList.java b/src/main/java/ch/zhaw/gartenverwaltung/io/JsonTaskList.java
index 4092330..869783c 100644
--- a/src/main/java/ch/zhaw/gartenverwaltung/io/JsonTaskList.java
+++ b/src/main/java/ch/zhaw/gartenverwaltung/io/JsonTaskList.java
@@ -67,7 +67,7 @@ public class JsonTaskList implements TaskList {
      * @see TaskList#getTaskList(LocalDate, LocalDate)
      */
     @Override
-    public List<Task> getTaskList(LocalDate start, LocalDate end) throws IOException{
+    public synchronized List<Task> getTaskList(LocalDate start, LocalDate end) throws IOException{
         if(taskMap.isEmpty()) {
             loadTaskListFromFile();
         }
@@ -80,7 +80,7 @@ public class JsonTaskList implements TaskList {
      * @return List of Tasks for given Crop
      */
     @Override
-    public List<Task> getTaskForCrop(long cropId) throws IOException {
+    public synchronized List<Task> getTaskForCrop(long cropId) throws IOException {
         if(taskMap.isEmpty()) {
             loadTaskListFromFile();
         }
@@ -111,7 +111,7 @@ public class JsonTaskList implements TaskList {
      * @see TaskList#saveTask(Task)
      */
     @Override
-    public void saveTask(Task task) throws IOException {
+    public synchronized void saveTask(Task task) throws IOException {
         if(taskMap.isEmpty()) {
             loadTaskListFromFile();
         }
diff --git a/src/main/java/ch/zhaw/gartenverwaltung/models/GardenSchedule.java b/src/main/java/ch/zhaw/gartenverwaltung/models/GardenSchedule.java
index 932d6b5..2e3eb3d 100644
--- a/src/main/java/ch/zhaw/gartenverwaltung/models/GardenSchedule.java
+++ b/src/main/java/ch/zhaw/gartenverwaltung/models/GardenSchedule.java
@@ -3,6 +3,7 @@ package ch.zhaw.gartenverwaltung.models;
 import ch.zhaw.gartenverwaltung.Settings;
 import ch.zhaw.gartenverwaltung.io.*;
 import ch.zhaw.gartenverwaltung.types.*;
+import javafx.application.Platform;
 import javafx.beans.property.ListProperty;
 import javafx.beans.property.SimpleListProperty;
 import javafx.collections.FXCollections;
@@ -32,7 +33,13 @@ public class GardenSchedule {
         this.taskList = taskList;
         this.plantList = plantList;
         TaskList.TaskListObserver taskListObserver = newTaskList -> {
-            getTasksUpcomingWeek();
+            Platform.runLater(() -> {
+                try {
+                    getTasksUpcomingWeek();
+                } catch (IOException e) {
+                    throw new RuntimeException(e);
+                }
+            });
         };
         setTaskListObserver(taskListObserver);
     }
diff --git a/src/main/java/ch/zhaw/gartenverwaltung/types/Task.java b/src/main/java/ch/zhaw/gartenverwaltung/types/Task.java
index 017b18f..4136d1d 100644
--- a/src/main/java/ch/zhaw/gartenverwaltung/types/Task.java
+++ b/src/main/java/ch/zhaw/gartenverwaltung/types/Task.java
@@ -104,7 +104,7 @@ public class Task {
      * @return Whether the Task is within the given range
      */
     public boolean isInTimePeriod(LocalDate searchStartDate, LocalDate searchEndDate) {
-        return endDate.isAfter(searchStartDate) && startDate.isBefore(searchEndDate);
+        return endDate.isAfter(searchStartDate) && startDate.isBefore(searchEndDate) || (nextExecution != null && nextExecution.isBefore(searchEndDate) && nextExecution.isAfter(searchStartDate));
     }
 
     /**
diff --git a/src/test/java/ch/zhaw/gartenverwaltung/io/JsonTaskListTest.java b/src/test/java/ch/zhaw/gartenverwaltung/io/JsonTaskListTest.java
index 00e21e3..2a515d7 100644
--- a/src/test/java/ch/zhaw/gartenverwaltung/io/JsonTaskListTest.java
+++ b/src/test/java/ch/zhaw/gartenverwaltung/io/JsonTaskListTest.java
@@ -130,7 +130,7 @@ public class JsonTaskListTest {
     }
 
     @Test
-    void testSubscription() {
+    void testSubscription() throws IOException {
         TaskList.TaskListObserver mockObs = Mockito.mock(TaskList.TaskListObserver.class);
         testDatabase.subscribe(mockObs);
         try {