diff --git a/src/com/android/settings/fuelgauge/batterytip/AnomalyCleanupJobService.java b/src/com/android/settings/fuelgauge/batterytip/AnomalyCleanupJobService.java
index 9e57433..d602194 100644
--- a/src/com/android/settings/fuelgauge/batterytip/AnomalyCleanupJobService.java
+++ b/src/com/android/settings/fuelgauge/batterytip/AnomalyCleanupJobService.java
@@ -64,7 +64,7 @@
         final BatteryTipPolicy policy = new BatteryTipPolicy(this);
         ThreadUtils.postOnBackgroundThread(() -> {
             batteryDatabaseManager.deleteAllAnomaliesBeforeTimeStamp(
-                    System.currentTimeMillis() - TimeUnit.HOURS.toMillis(
+                    System.currentTimeMillis() - TimeUnit.DAYS.toMillis(
                             policy.dataHistoryRetainDay));
             jobFinished(params, false /* wantsReschedule */);
         });
diff --git a/tests/robotests/src/com/android/settings/fuelgauge/batterytip/AnomalyCleanupJobServiceTest.java b/tests/robotests/src/com/android/settings/fuelgauge/batterytip/AnomalyCleanupJobServiceTest.java
index a39276d..f600d41 100644
--- a/tests/robotests/src/com/android/settings/fuelgauge/batterytip/AnomalyCleanupJobServiceTest.java
+++ b/tests/robotests/src/com/android/settings/fuelgauge/batterytip/AnomalyCleanupJobServiceTest.java
@@ -17,36 +17,55 @@
 package com.android.settings.fuelgauge.batterytip;
 
 import static com.google.common.truth.Truth.assertThat;
+
 import static org.junit.Assert.assertEquals;
 import static org.mockito.Matchers.any;
+import static org.mockito.Matchers.anyBoolean;
+import static org.mockito.Mockito.doNothing;
 import static org.mockito.Mockito.spy;
 import static org.mockito.Mockito.times;
 import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
-import static org.robolectric.RuntimeEnvironment.application;
 
 import android.app.job.JobInfo;
+import android.app.job.JobParameters;
 import android.app.job.JobScheduler;
 import android.content.Context;
 
 import com.android.settings.R;
+import com.android.settings.testutils.DatabaseTestUtils;
 import com.android.settings.testutils.SettingsRobolectricTestRunner;
+import com.android.settings.testutils.shadow.ShadowThreadUtils;
 
+import org.junit.After;
 import org.junit.Before;
 import org.junit.Test;
 import org.junit.runner.RunWith;
+import org.mockito.Mock;
 import org.mockito.MockitoAnnotations;
+import org.robolectric.Robolectric;
 import org.robolectric.RuntimeEnvironment;
 import org.robolectric.Shadows;
+import org.robolectric.annotation.Config;
 import org.robolectric.shadows.ShadowJobScheduler;
 
 import java.util.List;
 import java.util.concurrent.TimeUnit;
 
 @RunWith(SettingsRobolectricTestRunner.class)
+@Config(shadows = ShadowThreadUtils.class)
 public class AnomalyCleanupJobServiceTest {
+    private static final int UID = 1234;
+    private static final String PACKAGE_NAME = "com.android.package";
+    private static final String PACKAGE_NAME_OLD = "com.android.package.old";
+    private static final int ANOMALY_TYPE = 1;
+    private static final long TIMESTAMP_NOW = System.currentTimeMillis();
+    private static final long TIMESTAMP_31_DAYS_BEFORE = TIMESTAMP_NOW - TimeUnit.DAYS.toMillis(31);
+
     private Context mContext;
     private JobScheduler mJobScheduler;
+    @Mock
+    private JobParameters mParams;
 
     @Before
     public void setUp() {
@@ -57,12 +76,17 @@
         when(mContext.getSystemService(JobScheduler.class)).thenReturn(mJobScheduler);
     }
 
+    @After
+    public void cleanUp() {
+        DatabaseTestUtils.clearDb(mContext);
+    }
+
     @Test
-    public void testScheduleCleanUp() {
+    public void scheduleCleanUp() {
         AnomalyCleanupJobService.scheduleCleanUp(mContext);
 
         ShadowJobScheduler shadowJobScheduler =
-            Shadows.shadowOf(mContext.getSystemService(JobScheduler.class));
+                Shadows.shadowOf(mContext.getSystemService(JobScheduler.class));
         List<JobInfo> pendingJobs = shadowJobScheduler.getAllPendingJobs();
         assertEquals(1, pendingJobs.size());
         JobInfo pendingJob = pendingJobs.get(0);
@@ -74,10 +98,35 @@
     }
 
     @Test
-    public void testScheduleCleanUp_invokeTwice_onlyScheduleOnce() {
+    public void scheduleCleanUp_invokeTwice_onlyScheduleOnce() {
         AnomalyCleanupJobService.scheduleCleanUp(mContext);
         AnomalyCleanupJobService.scheduleCleanUp(mContext);
 
         verify(mJobScheduler, times(1)).schedule(any());
     }
+
+    @Test
+    public void onStartJob_cleanUpDataBefore30days() {
+        final BatteryDatabaseManager databaseManager = BatteryDatabaseManager.getInstance(mContext);
+        final AnomalyCleanupJobService service = spy(Robolectric.setupService(
+                AnomalyCleanupJobService.class));
+        doNothing().when(service).jobFinished(any(), anyBoolean());
+
+        // Insert two records, one is current and the other one is 31 days before
+        databaseManager.insertAnomaly(UID, PACKAGE_NAME, ANOMALY_TYPE,
+                AnomalyDatabaseHelper.State.NEW, TIMESTAMP_NOW);
+        databaseManager.insertAnomaly(UID, PACKAGE_NAME_OLD, ANOMALY_TYPE,
+                AnomalyDatabaseHelper.State.NEW, TIMESTAMP_31_DAYS_BEFORE);
+
+        service.onStartJob(mParams);
+
+        // In database, it only contains the current record
+        final List<AppInfo> appInfos = databaseManager.queryAllAnomalies(0,
+                AnomalyDatabaseHelper.State.NEW);
+        assertThat(appInfos).containsExactly(new AppInfo.Builder()
+                .setUid(UID)
+                .setPackageName(PACKAGE_NAME)
+                .addAnomalyType(ANOMALY_TYPE)
+                .build());
+    }
 }