diff --git a/app/build.gradle b/app/build.gradle
index 72d82d38..b3f150a5 100644
--- a/app/build.gradle
+++ b/app/build.gradle
@@ -9,7 +9,7 @@ android {
         minSdkVersion 17
         targetSdkVersion 23
         versionCode 224
-        versionName "3.0.0 Alpha24"
+        versionName "3.0.0 Alpha2"
         testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
         multiDexEnabled true
         ndk {
diff --git a/app/src/main/java/com/stardust/scriptdroid/timing/TimedTaskManager.java b/app/src/main/java/com/stardust/scriptdroid/timing/TimedTaskManager.java
index dfc660db..e7309433 100644
--- a/app/src/main/java/com/stardust/scriptdroid/timing/TimedTaskManager.java
+++ b/app/src/main/java/com/stardust/scriptdroid/timing/TimedTaskManager.java
@@ -49,6 +49,11 @@ public class TimedTaskManager {
             @Override
             public void onModelChanged(@NonNull TimedTask model, @NonNull BaseModel.Action action) {
                 mTimedTaskChanges.onNext(new ModelChange<>(model, action));
+                if (action == BaseModel.Action.DELETE && countTasks() == 0) {
+                    TimedTaskScheduler.stopRtcRepeating(mContext);
+                } else if (action == BaseModel.Action.INSERT) {
+                    TimedTaskScheduler.startRtcRepeatingIfNeeded(mContext);
+                }
             }
 
             @Override
@@ -132,4 +137,8 @@ public class TimedTaskManager {
         TimedTaskScheduler.cancel(mContext, task);
         TimedTaskScheduler.scheduleTaskIfNeeded(mContext, task);
     }
+
+    public long countTasks() {
+        return SQLite.select().from(TimedTask.class).count();
+    }
 }
diff --git a/app/src/main/java/com/stardust/scriptdroid/timing/TimedTaskScheduler.java b/app/src/main/java/com/stardust/scriptdroid/timing/TimedTaskScheduler.java
index b607e01c..3454bc46 100644
--- a/app/src/main/java/com/stardust/scriptdroid/timing/TimedTaskScheduler.java
+++ b/app/src/main/java/com/stardust/scriptdroid/timing/TimedTaskScheduler.java
@@ -33,29 +33,26 @@ public class TimedTaskScheduler extends BroadcastReceiver {
     }
 
     public static void checkTasks(Context context) {
-        AlarmManager alarmManager = (AlarmManager) context.getSystemService(Context.ALARM_SERVICE);
         TimedTaskManager.getInstance().getAllTasks()
                 .subscribeOn(Schedulers.io())
                 .observeOn(AndroidSchedulers.mainThread())
-                .subscribe(timedTask -> scheduleTaskIfNeeded(context, alarmManager, timedTask));
+                .subscribe(timedTask -> scheduleTaskIfNeeded(context, timedTask));
     }
 
-    public static void scheduleTaskIfNeeded(Context context, AlarmManager alarmManager, TimedTask timedTask) {
+    public static void scheduleTaskIfNeeded(Context context, TimedTask timedTask) {
         long millis = timedTask.getNextTime();
         if (timedTask.isScheduled() || millis - System.currentTimeMillis() > ONE_HOUR) {
             return;
         }
-        scheduleTask(context, alarmManager, timedTask, millis);
+        scheduleTask(context, timedTask, millis);
         TimedTaskManager.getInstance()
                 .notifyTaskScheduled(timedTask);
 
     }
 
-    public static void scheduleTaskIfNeeded(Context context, TimedTask timedTask) {
-        scheduleTaskIfNeeded(context, (AlarmManager) context.getSystemService(Context.ALARM_SERVICE), timedTask);
-    }
 
-    private static void scheduleTask(Context context, AlarmManager alarmManager, TimedTask timedTask, long millis) {
+    private static void scheduleTask(Context context, TimedTask timedTask, long millis) {
+        AlarmManager alarmManager = (AlarmManager) context.getSystemService(Context.ALARM_SERVICE);
         if (millis <= System.currentTimeMillis()) {
             context.sendBroadcast(timedTask.createIntent());
             return;
@@ -70,14 +67,34 @@ public class TimedTaskScheduler extends BroadcastReceiver {
     }
 
     public static void setupRepeating(Context context) {
+        if (TimedTaskManager.getInstance().countTasks() > 0) {
+            startRtcRepeatingIfNeeded(context);
+        }
+    }
+
+
+    public static void startRtcRepeatingIfNeeded(Context context) {
+        Log.v(LOG_TAG, "startRtcRepeating");
         AlarmManager alarmManager = (AlarmManager) context.getSystemService(Context.ALARM_SERVICE);
         alarmManager.setRepeating(AlarmManager.RTC_WAKEUP, System.currentTimeMillis() + 5000,
-                INTERVAL, PendingIntent.getBroadcast(context, REQUEST_CODE,
-                        new Intent(TimedTaskScheduler.ACTION_CHECK_TASK), PendingIntent.FLAG_UPDATE_CURRENT));
+                INTERVAL, createTaskCheckPendingIntent(context));
     }
 
+
     public static void cancel(Context context, TimedTask timedTask) {
         AlarmManager alarmManager = (AlarmManager) context.getSystemService(Context.ALARM_SERVICE);
         alarmManager.cancel(timedTask.createPendingIntent(context));
     }
+
+    public static void stopRtcRepeating(Context context) {
+        Log.v(LOG_TAG, "stopRtcRepeating");
+        AlarmManager alarmManager = (AlarmManager) context.getSystemService(Context.ALARM_SERVICE);
+        alarmManager.cancel(createTaskCheckPendingIntent(context));
+
+    }
+
+    private static PendingIntent createTaskCheckPendingIntent(Context context) {
+        return PendingIntent.getBroadcast(context, REQUEST_CODE,
+                new Intent(TimedTaskScheduler.ACTION_CHECK_TASK), PendingIntent.FLAG_UPDATE_CURRENT);
+    }
 }
diff --git a/app/src/main/java/com/stardust/scriptdroid/ui/main/task/Task.java b/app/src/main/java/com/stardust/scriptdroid/ui/main/task/Task.java
index c1b8ecfd..8526962f 100644
--- a/app/src/main/java/com/stardust/scriptdroid/ui/main/task/Task.java
+++ b/app/src/main/java/com/stardust/scriptdroid/ui/main/task/Task.java
@@ -1,5 +1,8 @@
 package com.stardust.scriptdroid.ui.main.task;
 
+import android.os.Parcel;
+import android.os.Parcelable;
+
 import com.stardust.autojs.engine.JavaScriptEngine;
 import com.stardust.autojs.engine.ScriptEngine;
 import com.stardust.autojs.engine.ScriptEngineFactory;
@@ -19,7 +22,7 @@ import org.joda.time.format.DateTimeFormat;
  * Created by Stardust on 2017/11/28.
  */
 
-public abstract class Task {
+public abstract class Task implements Parcelable {
 
     public abstract String getName();
 
@@ -29,6 +32,16 @@ public abstract class Task {
 
     public abstract String getEngineName();
 
+    @Override
+    public int describeContents() {
+        return 0;
+    }
+
+    @Override
+    public void writeToParcel(Parcel dest, int flags) {
+
+    }
+
     public static class PendingTask extends Task {
 
         private TimedTask mTimedTask;
diff --git a/app/src/main/java/com/stardust/scriptdroid/ui/main/task/TaskListRecyclerView.java b/app/src/main/java/com/stardust/scriptdroid/ui/main/task/TaskListRecyclerView.java
index 934a538d..3a63d4fd 100644
--- a/app/src/main/java/com/stardust/scriptdroid/ui/main/task/TaskListRecyclerView.java
+++ b/app/src/main/java/com/stardust/scriptdroid/ui/main/task/TaskListRecyclerView.java
@@ -108,8 +108,8 @@ public class TaskListRecyclerView extends ThemeColorRecyclerView implements Scri
         for (TaskGroup group : mTaskGroups) {
             group.refresh();
         }
-        mAdapter.notifyParentChanged(0);
-        mAdapter.notifyParentChanged(1);
+        mAdapter = new Adapter(mTaskGroups);
+        setAdapter(mAdapter);
         //notifyDataSetChanged not working...
     }
 
@@ -286,4 +286,4 @@ public class TaskListRecyclerView extends ThemeColorRecyclerView implements Scri
         }
     }
 
-}
+}
\ No newline at end of file