diff --git a/res/values/strings.xml b/res/values/strings.xml
index 139fd5f6865..d30a95a614d 100644
--- a/res/values/strings.xml
+++ b/res/values/strings.xml
@@ -2807,6 +2807,12 @@
     <!-- Night display slice screen, subtitle of intensity setting when night light is off. [CHAR LIMIT=30] -->
     <string name="night_display_not_currently_on">Night Light not currently on</string>
 
+    <!-- Twilight Mode -->
+    <!-- When location mode is off, twilight scheduling does not function. [CHAR LIMIT=40] -->
+    <string name="twilight_mode_location_off_dialog_message">Device location needed to determine you sunset to sunrise</string>
+    <!-- When location mode is off, twilight scheduling does not function. [CHAR LIMIT=40] -->
+    <string name="twilight_mode_launch_location">Turn on location</string>
+
     <!--    Dark ui screen-->
     <!-- Display settings screen, activation button action for manual mode. [CHAR LIMIT=40] -->
     <string name="dark_ui_activation_on_manual">Turn on now</string>
diff --git a/src/com/android/settings/display/NightDisplayAutoModePreferenceController.java b/src/com/android/settings/display/NightDisplayAutoModePreferenceController.java
index 121b062a0e6..fb2dbc3b903 100644
--- a/src/com/android/settings/display/NightDisplayAutoModePreferenceController.java
+++ b/src/com/android/settings/display/NightDisplayAutoModePreferenceController.java
@@ -18,6 +18,7 @@ package com.android.settings.display;
 
 import android.content.Context;
 import android.hardware.display.ColorDisplayManager;
+import android.location.LocationManager;
 
 import androidx.preference.DropDownPreference;
 import androidx.preference.Preference;
@@ -29,12 +30,14 @@ import com.android.settings.core.BasePreferenceController;
 public class NightDisplayAutoModePreferenceController extends BasePreferenceController
         implements Preference.OnPreferenceChangeListener {
 
+    private final LocationManager mLocationManager;
     private DropDownPreference mPreference;
     private ColorDisplayManager mColorDisplayManager;
 
     public NightDisplayAutoModePreferenceController(Context context, String key) {
         super(context, key);
         mColorDisplayManager = context.getSystemService(ColorDisplayManager.class);
+        mLocationManager = context.getSystemService(LocationManager.class);
     }
 
     @Override
@@ -68,6 +71,11 @@ public class NightDisplayAutoModePreferenceController extends BasePreferenceCont
 
     @Override
     public final boolean onPreferenceChange(Preference preference, Object newValue) {
+        if (String.valueOf(ColorDisplayManager.AUTO_MODE_TWILIGHT).equals(newValue)
+                && !mLocationManager.isLocationEnabled()) {
+            TwilightLocationDialog.show(mContext);
+            return false;
+        }
         return mColorDisplayManager.setNightDisplayAutoMode(Integer.parseInt((String) newValue));
     }
 }
diff --git a/src/com/android/settings/display/TwilightLocationDialog.java b/src/com/android/settings/display/TwilightLocationDialog.java
new file mode 100644
index 00000000000..1a2cf673611
--- /dev/null
+++ b/src/com/android/settings/display/TwilightLocationDialog.java
@@ -0,0 +1,47 @@
+/*
+ * Copyright (C) 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.settings.display;
+
+import android.app.AlertDialog;
+import android.content.Context;
+import android.content.Intent;
+import android.util.Log;
+
+import com.android.settings.R;
+import com.android.settings.Settings;
+
+/*
+ * This class lauches a dialog when users try to use twilight scheduling without
+ * turning on location services
+ */
+public class TwilightLocationDialog {
+    public static String TAG = "TwilightLocationDialog";
+
+    public static void show(Context context) {
+        final AlertDialog dialog = new AlertDialog.Builder(context)
+                .setPositiveButton(R.string.twilight_mode_launch_location, ((dialog1, which) -> {
+                    Log.d(TAG, "clicked forget");
+                    final Intent intent = new Intent();
+                    intent.setClass(context, Settings.LocationSettingsActivity.class);
+                    context.startActivity(intent);
+                }))
+                .setNegativeButton(R.string.cancel, null /* listener */)
+                .setMessage(R.string.twilight_mode_location_off_dialog_message)
+                .create();
+        dialog.show();
+    }
+}
diff --git a/src/com/android/settings/display/darkmode/DarkModeScheduleSelectorController.java b/src/com/android/settings/display/darkmode/DarkModeScheduleSelectorController.java
index ea7fc036ee4..6acaf8292a4 100644
--- a/src/com/android/settings/display/darkmode/DarkModeScheduleSelectorController.java
+++ b/src/com/android/settings/display/darkmode/DarkModeScheduleSelectorController.java
@@ -17,6 +17,7 @@ package com.android.settings.display.darkmode;
 import android.app.UiModeManager;
 import android.content.Context;
 import android.content.res.Configuration;
+import android.location.LocationManager;
 import android.os.PowerManager;
 
 import androidx.preference.DropDownPreference;
@@ -25,6 +26,7 @@ import androidx.preference.PreferenceScreen;
 
 import com.android.settings.R;
 import com.android.settings.core.BasePreferenceController;
+import com.android.settings.display.TwilightLocationDialog;
 
 /**
  * Controller for the dark ui option dropdown
@@ -35,12 +37,14 @@ public class DarkModeScheduleSelectorController extends BasePreferenceController
     private final UiModeManager mUiModeManager;
     private PowerManager mPowerManager;
     private DropDownPreference mPreference;
+    private LocationManager mLocationManager;
     private int mCurrentMode;
 
     public DarkModeScheduleSelectorController(Context context, String key) {
         super(context, key);
         mUiModeManager = context.getSystemService(UiModeManager.class);
         mPowerManager = context.getSystemService(PowerManager.class);
+        mLocationManager = context.getSystemService(LocationManager.class);
     }
 
     @Override
@@ -93,6 +97,10 @@ public class DarkModeScheduleSelectorController extends BasePreferenceController
             mUiModeManager.setNightMode(mode);
         } else if (mCurrentMode == mPreference.findIndexOfValue(
                 mContext.getString(R.string.dark_ui_auto_mode_auto))) {
+            if (!mLocationManager.isLocationEnabled()) {
+                TwilightLocationDialog.show(mContext);
+                return false;
+            }
             mUiModeManager.setNightMode(UiModeManager.MODE_NIGHT_AUTO);
         } else if (mCurrentMode == mPreference.findIndexOfValue(
                 mContext.getString(R.string.dark_ui_auto_mode_custom))) {
diff --git a/tests/robotests/src/com/android/settings/display/darkmode/DarkModeScheduleSelectorControllerTest.java b/tests/robotests/src/com/android/settings/display/darkmode/DarkModeScheduleSelectorControllerTest.java
index 8afda73e09e..d741235ff56 100644
--- a/tests/robotests/src/com/android/settings/display/darkmode/DarkModeScheduleSelectorControllerTest.java
+++ b/tests/robotests/src/com/android/settings/display/darkmode/DarkModeScheduleSelectorControllerTest.java
@@ -28,6 +28,7 @@ import static org.mockito.Mockito.when;
 
 import android.app.UiModeManager;
 import android.content.Context;
+import android.location.LocationManager;
 import android.os.PowerManager;
 
 import androidx.preference.DropDownPreference;
@@ -55,6 +56,8 @@ public class DarkModeScheduleSelectorControllerTest {
     @Mock
     private UiModeManager mUiService;
     @Mock
+    private LocationManager mLocationManager;
+    @Mock
     private PowerManager mPM;
 
     @Before
@@ -63,6 +66,7 @@ public class DarkModeScheduleSelectorControllerTest {
         mContext = spy(RuntimeEnvironment.application);
         when(mContext.getSystemService(UiModeManager.class)).thenReturn(mUiService);
         when(mContext.getSystemService(PowerManager.class)).thenReturn(mPM);
+        when(mContext.getSystemService(LocationManager.class)).thenReturn(mLocationManager);
         when(mContext.getString(R.string.dark_ui_auto_mode_never)).thenReturn("never");
         when(mContext.getString(R.string.dark_ui_auto_mode_auto)).thenReturn("auto");
         when(mContext.getString(R.string.dark_ui_auto_mode_custom)).thenReturn("custom");
@@ -72,6 +76,7 @@ public class DarkModeScheduleSelectorControllerTest {
                 mContext.getString(R.string.dark_ui_auto_mode_auto)
         });
         doNothing().when(mPreference).setValueIndex(anyInt());
+        when(mLocationManager.isLocationEnabled()).thenReturn(true);
         when(mScreen.findPreference(anyString())).thenReturn(mPreference);
         when(mUiService.setNightModeActivated(anyBoolean())).thenReturn(true);
         mController = new DarkModeScheduleSelectorController(mContext, mPreferenceKey);
@@ -96,6 +101,15 @@ public class DarkModeScheduleSelectorControllerTest {
         verify(mPreference).setValueIndex(0);
     }
 
+    @Test
+    public void nightMode_selectNightMode_locationOff() {
+        when(mLocationManager.isLocationEnabled()).thenReturn(false);
+        mController.onPreferenceChange(mPreference,
+                mContext.getString(R.string.dark_ui_auto_mode_never));
+        assertFalse(mController.onPreferenceChange(mPreference,
+                mContext.getString(R.string.dark_ui_auto_mode_auto)));
+    }
+
     @Test
     public void nightMode_updateStateNone_dropDownValueChangedToAuto() {
         when(mUiService.getNightMode()).thenReturn(UiModeManager.MODE_NIGHT_AUTO);