diff --git a/services/tests/servicestests/src/com/android/server/timedetector/SimpleTimeZoneDetectorStrategyTest.java b/services/tests/servicestests/src/com/android/server/timedetector/SimpleTimeZoneDetectorStrategyTest.java
new file mode 100644
index 0000000..e4b3b13
--- /dev/null
+++ b/services/tests/servicestests/src/com/android/server/timedetector/SimpleTimeZoneDetectorStrategyTest.java
@@ -0,0 +1,68 @@
+/*
+ * Copyright (C) 2018 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.server.timedetector;
+
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.never;
+import static org.mockito.Mockito.verify;
+
+import android.app.timedetector.TimeSignal;
+import android.support.test.runner.AndroidJUnit4;
+import android.util.TimestampedValue;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+@RunWith(AndroidJUnit4.class)
+public class SimpleTimeZoneDetectorStrategyTest {
+
+    private TimeDetectorStrategy.Callback mMockCallback;
+
+    private SimpleTimeDetectorStrategy mSimpleTimeZoneDetectorStrategy;
+
+    @Before
+    public void setUp() {
+        mMockCallback = mock(TimeDetectorStrategy.Callback.class);
+        mSimpleTimeZoneDetectorStrategy = new SimpleTimeDetectorStrategy();
+        mSimpleTimeZoneDetectorStrategy.initialize(mMockCallback);
+    }
+
+    @Test
+    public void testSuggestTime_nitz() {
+        TimestampedValue<Long> utcTime = createUtcTime();
+        TimeSignal timeSignal = new TimeSignal(TimeSignal.SOURCE_ID_NITZ, utcTime);
+
+        mSimpleTimeZoneDetectorStrategy.suggestTime(timeSignal);
+
+        verify(mMockCallback).setTime(utcTime);
+    }
+
+    @Test
+    public void testSuggestTime_unknownSource() {
+        TimestampedValue<Long> utcTime = createUtcTime();
+        TimeSignal timeSignal = new TimeSignal("unknown", utcTime);
+        mSimpleTimeZoneDetectorStrategy.suggestTime(timeSignal);
+
+        verify(mMockCallback, never()).setTime(any());
+    }
+
+    private static TimestampedValue<Long> createUtcTime() {
+        return new TimestampedValue<>(321L, 123456L);
+    }
+}