diff --git a/native/jni/src/suggest/policyimpl/dictionary/structure/v4/ver4_patricia_trie_policy.cpp b/native/jni/src/suggest/policyimpl/dictionary/structure/v4/ver4_patricia_trie_policy.cpp
index 82cd95e6b..3447dce93 100644
--- a/native/jni/src/suggest/policyimpl/dictionary/structure/v4/ver4_patricia_trie_policy.cpp
+++ b/native/jni/src/suggest/policyimpl/dictionary/structure/v4/ver4_patricia_trie_policy.cpp
@@ -36,6 +36,11 @@ const char *const Ver4PatriciaTriePolicy::MAX_UNIGRAM_COUNT_QUERY = "MAX_UNIGRAM
 const char *const Ver4PatriciaTriePolicy::MAX_BIGRAM_COUNT_QUERY = "MAX_BIGRAM_COUNT";
 const char *const Ver4PatriciaTriePolicy::SET_NEEDS_TO_DECAY_FOR_TESTING_QUERY =
         "SET_NEEDS_TO_DECAY_FOR_TESTING";
+const char *const Ver4PatriciaTriePolicy::SET_CURRENT_TIME_FOR_TESTING_QUERY_FORMAT =
+        "SET_CURRENT_TIME_FOR_TESTING:%d";
+const char *const Ver4PatriciaTriePolicy::GET_CURRENT_TIME_QUERY = "GET_CURRENT_TIME";
+const char *const Ver4PatriciaTriePolicy::QUIT_TIMEKEEPER_TEST_MODE_QUERY =
+        "QUIT_TIMEKEEPER_TEST_MODE";
 const int Ver4PatriciaTriePolicy::MARGIN_TO_REFUSE_DYNAMIC_OPERATIONS = 1024;
 const int Ver4PatriciaTriePolicy::MIN_DICT_SIZE_TO_REFUSE_DYNAMIC_OPERATIONS =
         Ver4DictConstants::MAX_DICTIONARY_SIZE - MARGIN_TO_REFUSE_DYNAMIC_OPERATIONS;
@@ -290,6 +295,7 @@ bool Ver4PatriciaTriePolicy::needsToRunGC(const bool mindsBlockByGC) const {
 void Ver4PatriciaTriePolicy::getProperty(const char *const query, const int queryLength,
         char *const outResult, const int maxResultLength) {
     const int compareLength = queryLength + 1 /* terminator */;
+    int timestamp = NOT_A_TIMESTAMP;
     if (strncmp(query, UNIGRAM_COUNT_QUERY, compareLength) == 0) {
         snprintf(outResult, maxResultLength, "%d", mUnigramCount);
     } else if (strncmp(query, BIGRAM_COUNT_QUERY, compareLength) == 0) {
@@ -304,6 +310,12 @@ void Ver4PatriciaTriePolicy::getProperty(const char *const query, const int quer
                         static_cast<int>(Ver4DictConstants::MAX_DICTIONARY_SIZE));
     } else if (strncmp(query, SET_NEEDS_TO_DECAY_FOR_TESTING_QUERY, compareLength) == 0) {
         mNeedsToDecayForTesting = true;
+    } else if (sscanf(query, SET_CURRENT_TIME_FOR_TESTING_QUERY_FORMAT, &timestamp) == 1) {
+        TimeKeeper::startTestModeWithForceCurrentTime(timestamp);
+    } else if (strncmp(query, GET_CURRENT_TIME_QUERY, compareLength) == 0) {
+        snprintf(outResult, maxResultLength, "%d", TimeKeeper::peekCurrentTime());
+    } else if (strncmp(query, QUIT_TIMEKEEPER_TEST_MODE_QUERY, compareLength) == 0) {
+        TimeKeeper::stopTestMode();
     }
 }
 
diff --git a/native/jni/src/suggest/policyimpl/dictionary/structure/v4/ver4_patricia_trie_policy.h b/native/jni/src/suggest/policyimpl/dictionary/structure/v4/ver4_patricia_trie_policy.h
index db4e8d21c..d2d2ead50 100644
--- a/native/jni/src/suggest/policyimpl/dictionary/structure/v4/ver4_patricia_trie_policy.h
+++ b/native/jni/src/suggest/policyimpl/dictionary/structure/v4/ver4_patricia_trie_policy.h
@@ -118,6 +118,9 @@ class Ver4PatriciaTriePolicy : public DictionaryStructureWithBufferPolicy {
     static const char *const MAX_UNIGRAM_COUNT_QUERY;
     static const char *const MAX_BIGRAM_COUNT_QUERY;
     static const char *const SET_NEEDS_TO_DECAY_FOR_TESTING_QUERY;
+    static const char *const SET_CURRENT_TIME_FOR_TESTING_QUERY_FORMAT;
+    static const char *const GET_CURRENT_TIME_QUERY;
+    static const char *const QUIT_TIMEKEEPER_TEST_MODE_QUERY;
     // When the dictionary size is near the maximum size, we have to refuse dynamic operations to
     // prevent the dictionary from overflowing.
     static const int MARGIN_TO_REFUSE_DYNAMIC_OPERATIONS;
diff --git a/tests/src/com/android/inputmethod/latin/BinaryDictionaryDecayingTests.java b/tests/src/com/android/inputmethod/latin/BinaryDictionaryDecayingTests.java
index 95504ef14..224e70da0 100644
--- a/tests/src/com/android/inputmethod/latin/BinaryDictionaryDecayingTests.java
+++ b/tests/src/com/android/inputmethod/latin/BinaryDictionaryDecayingTests.java
@@ -37,9 +37,13 @@ public class BinaryDictionaryDecayingTests extends AndroidTestCase {
     private static final String TEST_LOCALE = "test";
 
     // Note that these are corresponding definitions in native code in
-    // latinime::DynamicPatriciaTriePolicy.
+    // latinime::Ver4PatriciaTriePolicy.
     private static final String SET_NEEDS_TO_DECAY_FOR_TESTING_KEY =
             "SET_NEEDS_TO_DECAY_FOR_TESTING";
+    private static final String SET_CURRENT_TIME_FOR_TESTING_QUERY =
+            "SET_CURRENT_TIME_FOR_TESTING";
+    private static final String GET_CURRENT_TIME_QUERY = "GET_CURRENT_TIME";
+    private static final String QUIT_TIMEKEEPER_TEST_MODE_QUERY = "QUIT_TIMEKEEPER_TEST_MODE";
 
     private static final int DUMMY_PROBABILITY = 0;
 
@@ -114,6 +118,45 @@ public class BinaryDictionaryDecayingTests extends AndroidTestCase {
         }
     }
 
+    private static int getCurrentTime(final BinaryDictionary binaryDictionary) {
+        return Integer.parseInt(binaryDictionary.getPropertyForTests(GET_CURRENT_TIME_QUERY));
+    }
+
+    private static void setCurrentTime(final BinaryDictionary binaryDictionary,
+            final int currentTime) {
+        final String query = SET_CURRENT_TIME_FOR_TESTING_QUERY + ":" + currentTime;
+        binaryDictionary.getPropertyForTests(query);
+    }
+
+    public void testControllCurrentTime() {
+        testControllCurrentTime(FormatSpec.VERSION4);
+    }
+
+    private void testControllCurrentTime(final int formatVersion) {
+        final int TEST_COUNT = 1000;
+        final long seed = System.currentTimeMillis();
+        final Random random = new Random(seed);
+        File dictFile = null;
+        try {
+            dictFile = createEmptyDictionaryAndGetFile("TestBinaryDictionary", formatVersion);
+        } catch (IOException e) {
+            fail("IOException while writing an initial dictionary : " + e);
+        }
+        BinaryDictionary binaryDictionary = new BinaryDictionary(dictFile.getAbsolutePath(),
+                0 /* offset */, dictFile.length(), true /* useFullEditDistance */,
+                Locale.getDefault(), TEST_LOCALE, true /* isUpdatable */);
+        final int startTime = getCurrentTime(binaryDictionary);
+        for (int i = 0; i < TEST_COUNT; i++) {
+            final int currentTime = random.nextInt(Integer.MAX_VALUE);
+            setCurrentTime(binaryDictionary, currentTime);
+            assertEquals(currentTime, getCurrentTime(binaryDictionary));
+        }
+        binaryDictionary.getPropertyForTests(QUIT_TIMEKEEPER_TEST_MODE_QUERY);
+        final int endTime = getCurrentTime(binaryDictionary);
+        final int MAX_ALLOWED_ELAPSED_TIME = 10;
+        assertTrue(startTime <= endTime && endTime <= startTime + MAX_ALLOWED_ELAPSED_TIME);
+    }
+
     public void testAddValidAndInvalidWords() {
         testAddValidAndInvalidWords(4 /* formatVersion */);
     }