diff --git a/api/current.txt b/api/current.txt
index 9bc3150..022c8ba 100644
--- a/api/current.txt
+++ b/api/current.txt
@@ -33036,14 +33036,14 @@
   }
 
   public final class SystemClock {
+    method public static java.time.Clock currentNetworkTimeClock();
+    method public static long currentNetworkTimeMillis();
     method public static long currentThreadTimeMillis();
     method public static long elapsedRealtime();
-    method public static java.time.Clock elapsedRealtimeClock();
     method public static long elapsedRealtimeNanos();
     method public static boolean setCurrentTimeMillis(long);
     method public static void sleep(long);
     method public static long uptimeMillis();
-    method public static java.time.Clock uptimeMillisClock();
   }
 
   public class TestLooperManager {
diff --git a/api/removed.txt b/api/removed.txt
index 2aab223..55022f3 100644
--- a/api/removed.txt
+++ b/api/removed.txt
@@ -257,6 +257,12 @@
     ctor public RecoverySystem();
   }
 
+  public final class SystemClock {
+    method public static java.time.Clock elapsedRealtimeClock();
+    method public static java.time.Clock uptimeClock();
+    method public static deprecated java.time.Clock uptimeMillisClock();
+  }
+
   public class TestLooperManager {
     method public deprecated android.os.MessageQueue getQueue();
   }
diff --git a/core/java/android/app/IAlarmManager.aidl b/core/java/android/app/IAlarmManager.aidl
index 7b05b49..ded4c49 100644
--- a/core/java/android/app/IAlarmManager.aidl
+++ b/core/java/android/app/IAlarmManager.aidl
@@ -37,4 +37,5 @@
     void remove(in PendingIntent operation, in IAlarmListener listener);
     long getNextWakeFromIdleTime();
     AlarmManager.AlarmClockInfo getNextAlarmClock(int userId);
+    long currentNetworkTimeMillis();
 }
diff --git a/core/java/android/os/BestClock.java b/core/java/android/os/BestClock.java
new file mode 100644
index 0000000..aa066b6
--- /dev/null
+++ b/core/java/android/os/BestClock.java
@@ -0,0 +1,58 @@
+/*
+ * 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 android.os;
+
+import android.util.Log;
+
+import java.time.Clock;
+import java.time.DateTimeException;
+import java.time.ZoneId;
+import java.util.Arrays;
+
+/**
+ * Single {@link Clock} that will return the best available time from a set of
+ * prioritized {@link Clock} instances.
+ * <p>
+ * For example, when {@link SystemClock#currentNetworkTimeClock()} isn't able to
+ * provide the time, this class could use {@link Clock#systemUTC()} instead.
+ *
+ * @hide
+ */
+public class BestClock extends SimpleClock {
+    private static final String TAG = "BestClock";
+
+    private final Clock[] clocks;
+
+    public BestClock(ZoneId zone, Clock... clocks) {
+        super(zone);
+        this.clocks = clocks;
+    }
+
+    @Override
+    public long millis() {
+        for (Clock clock : clocks) {
+            try {
+                return clock.millis();
+            } catch (DateTimeException e) {
+                // Ignore and attempt the next clock
+                Log.w(TAG, e.toString());
+            }
+        }
+        throw new DateTimeException(
+                "No clocks in " + Arrays.toString(clocks) + " were able to provide time");
+    }
+}
diff --git a/core/java/android/os/SimpleClock.java b/core/java/android/os/SimpleClock.java
new file mode 100644
index 0000000..efc271f54
--- /dev/null
+++ b/core/java/android/os/SimpleClock.java
@@ -0,0 +1,53 @@
+/*
+ * 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 android.os;
+
+import java.time.Clock;
+import java.time.Instant;
+import java.time.ZoneId;
+
+/** {@hide} */
+public abstract class SimpleClock extends Clock {
+    private final ZoneId zone;
+
+    public SimpleClock(ZoneId zone) {
+        this.zone = zone;
+    }
+
+    @Override
+    public ZoneId getZone() {
+        return zone;
+    }
+
+    @Override
+    public Clock withZone(ZoneId zone) {
+        return new SimpleClock(zone) {
+            @Override
+            public long millis() {
+                return SimpleClock.this.millis();
+            }
+        };
+    }
+
+    @Override
+    public abstract long millis();
+
+    @Override
+    public Instant instant() {
+        return Instant.ofEpochMilli(millis());
+    }
+}
diff --git a/core/java/android/os/SystemClock.java b/core/java/android/os/SystemClock.java
index c52c22d..0f70427 100644
--- a/core/java/android/os/SystemClock.java
+++ b/core/java/android/os/SystemClock.java
@@ -24,8 +24,7 @@
 import dalvik.annotation.optimization.CriticalNative;
 
 import java.time.Clock;
-import java.time.Instant;
-import java.time.ZoneId;
+import java.time.DateTimeException;
 import java.time.ZoneOffset;
 
 /**
@@ -148,8 +147,8 @@
      * @return if the clock was successfully set to the specified time.
      */
     public static boolean setCurrentTimeMillis(long millis) {
-        IBinder b = ServiceManager.getService(Context.ALARM_SERVICE);
-        IAlarmManager mgr = IAlarmManager.Stub.asInterface(b);
+        final IAlarmManager mgr = IAlarmManager.Stub
+                .asInterface(ServiceManager.getService(Context.ALARM_SERVICE));
         if (mgr == null) {
             return false;
         }
@@ -174,27 +173,25 @@
     native public static long uptimeMillis();
 
     /**
+     * @removed
+     */
+    @Deprecated
+    public static @NonNull Clock uptimeMillisClock() {
+        return uptimeClock();
+    }
+
+    /**
      * Return {@link Clock} that starts at system boot, not counting time spent
      * in deep sleep.
+     *
+     * @removed
      */
-    public static @NonNull Clock uptimeMillisClock() {
-        return new Clock() {
-            @Override
-            public ZoneId getZone() {
-                return ZoneOffset.UTC;
-            }
-            @Override
-            public Clock withZone(ZoneId zone) {
-                throw new UnsupportedOperationException();
-            }
+    public static @NonNull Clock uptimeClock() {
+        return new SimpleClock(ZoneOffset.UTC) {
             @Override
             public long millis() {
                 return SystemClock.uptimeMillis();
             }
-            @Override
-            public Instant instant() {
-                return Instant.ofEpochMilli(millis());
-            }
         };
     }
 
@@ -209,25 +206,15 @@
     /**
      * Return {@link Clock} that starts at system boot, including time spent in
      * sleep.
+     *
+     * @removed
      */
     public static @NonNull Clock elapsedRealtimeClock() {
-        return new Clock() {
-            @Override
-            public ZoneId getZone() {
-                return ZoneOffset.UTC;
-            }
-            @Override
-            public Clock withZone(ZoneId zone) {
-                throw new UnsupportedOperationException();
-            }
+        return new SimpleClock(ZoneOffset.UTC) {
             @Override
             public long millis() {
                 return SystemClock.elapsedRealtime();
             }
-            @Override
-            public Instant instant() {
-                return Instant.ofEpochMilli(millis());
-            }
         };
     }
 
@@ -266,4 +253,62 @@
      */
     @CriticalNative
     public static native long currentTimeMicro();
+
+    /**
+     * Returns milliseconds since January 1, 1970 00:00:00.0 UTC, synchronized
+     * using a remote network source outside the device.
+     * <p>
+     * While the time returned by {@link System#currentTimeMillis()} can be
+     * adjusted by the user, the time returned by this method cannot be adjusted
+     * by the user. Note that synchronization may occur using an insecure
+     * network protocol, so the returned time should not be used for security
+     * purposes.
+     * <p>
+     * This performs no blocking network operations and returns values based on
+     * a recent successful synchronization event; it will either return a valid
+     * time or throw.
+     *
+     * @throws DateTimeException when no accurate network time can be provided.
+     */
+    public static long currentNetworkTimeMillis() {
+        final IAlarmManager mgr = IAlarmManager.Stub
+                .asInterface(ServiceManager.getService(Context.ALARM_SERVICE));
+        if (mgr != null) {
+            try {
+                return mgr.currentNetworkTimeMillis();
+            } catch (ParcelableException e) {
+                e.maybeRethrow(DateTimeException.class);
+                throw new RuntimeException(e);
+            } catch (RemoteException e) {
+                throw e.rethrowFromSystemServer();
+            }
+        } else {
+            throw new RuntimeException(new DeadSystemException());
+        }
+    }
+
+    /**
+     * Returns a {@link Clock} that starts at January 1, 1970 00:00:00.0 UTC,
+     * synchronized using a remote network source outside the device.
+     * <p>
+     * While the time returned by {@link System#currentTimeMillis()} can be
+     * adjusted by the user, the time returned by this method cannot be adjusted
+     * by the user. Note that synchronization may occur using an insecure
+     * network protocol, so the returned time should not be used for security
+     * purposes.
+     * <p>
+     * This performs no blocking network operations and returns values based on
+     * a recent successful synchronization event; it will either return a valid
+     * time or throw.
+     *
+     * @throws DateTimeException when no accurate network time can be provided.
+     */
+    public static @NonNull Clock currentNetworkTimeClock() {
+        return new SimpleClock(ZoneOffset.UTC) {
+            @Override
+            public long millis() {
+                return SystemClock.currentNetworkTimeMillis();
+            }
+        };
+    }
 }
diff --git a/core/java/android/provider/Settings.java b/core/java/android/provider/Settings.java
index c53d005..c6baec9 100644
--- a/core/java/android/provider/Settings.java
+++ b/core/java/android/provider/Settings.java
@@ -8760,6 +8760,7 @@
        /** {@hide} */
        public static final String NETSTATS_POLL_INTERVAL = "netstats_poll_interval";
        /** {@hide} */
+       @Deprecated
        public static final String NETSTATS_TIME_CACHE_MAX_AGE = "netstats_time_cache_max_age";
        /** {@hide} */
        public static final String NETSTATS_GLOBAL_ALERT_BYTES = "netstats_global_alert_bytes";
diff --git a/services/core/java/com/android/server/AlarmManagerService.java b/services/core/java/com/android/server/AlarmManagerService.java
index a422b7c..9cd3621 100644
--- a/services/core/java/com/android/server/AlarmManagerService.java
+++ b/services/core/java/com/android/server/AlarmManagerService.java
@@ -16,6 +16,13 @@
 
 package com.android.server;
 
+import static android.app.AlarmManager.ELAPSED_REALTIME;
+import static android.app.AlarmManager.ELAPSED_REALTIME_WAKEUP;
+import static android.app.AlarmManager.FLAG_ALLOW_WHILE_IDLE;
+import static android.app.AlarmManager.FLAG_ALLOW_WHILE_IDLE_UNRESTRICTED;
+import static android.app.AlarmManager.RTC;
+import static android.app.AlarmManager.RTC_WAKEUP;
+
 import android.annotation.UserIdInt;
 import android.app.Activity;
 import android.app.ActivityManager;
@@ -46,6 +53,7 @@
 import android.os.Handler;
 import android.os.IBinder;
 import android.os.Message;
+import android.os.ParcelableException;
 import android.os.PowerManager;
 import android.os.Process;
 import android.os.RemoteException;
@@ -62,6 +70,7 @@
 import android.util.ArraySet;
 import android.util.KeyValueListParser;
 import android.util.Log;
+import android.util.NtpTrustedTime;
 import android.util.Pair;
 import android.util.Slog;
 import android.util.SparseArray;
@@ -70,10 +79,18 @@
 import android.util.TimeUtils;
 import android.util.proto.ProtoOutputStream;
 
+import com.android.internal.annotations.GuardedBy;
+import com.android.internal.annotations.VisibleForTesting;
+import com.android.internal.util.ArrayUtils;
+import com.android.internal.util.DumpUtils;
+import com.android.internal.util.LocalLog;
+import com.android.server.AppStateTracker.Listener;
+
 import java.io.ByteArrayOutputStream;
 import java.io.FileDescriptor;
 import java.io.PrintWriter;
 import java.text.SimpleDateFormat;
+import java.time.DateTimeException;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Calendar;
@@ -88,21 +105,6 @@
 import java.util.TreeSet;
 import java.util.function.Predicate;
 
-import static android.app.AlarmManager.FLAG_ALLOW_WHILE_IDLE;
-import static android.app.AlarmManager.FLAG_ALLOW_WHILE_IDLE_UNRESTRICTED;
-import static android.app.AlarmManager.RTC_WAKEUP;
-import static android.app.AlarmManager.RTC;
-import static android.app.AlarmManager.ELAPSED_REALTIME_WAKEUP;
-import static android.app.AlarmManager.ELAPSED_REALTIME;
-
-import com.android.internal.annotations.GuardedBy;
-import com.android.internal.annotations.VisibleForTesting;
-import com.android.internal.util.ArrayUtils;
-import com.android.internal.util.DumpUtils;
-import com.android.internal.util.LocalLog;
-import com.android.internal.util.Preconditions;
-import com.android.server.AppStateTracker.Listener;
-
 /**
  * Alarm manager implementaion.
  *
@@ -1794,6 +1796,16 @@
         }
 
         @Override
+        public long currentNetworkTimeMillis() {
+            final NtpTrustedTime time = NtpTrustedTime.getInstance(getContext());
+            if (time.hasCache()) {
+                return time.currentTimeMillis();
+            } else {
+                throw new ParcelableException(new DateTimeException("Missing NTP fix"));
+            }
+        }
+
+        @Override
         protected void dump(FileDescriptor fd, PrintWriter pw, String[] args) {
             if (!DumpUtils.checkDumpAndUsageStatsPermission(getContext(), TAG, pw)) return;
 
diff --git a/services/core/java/com/android/server/NetworkTimeUpdateService.java b/services/core/java/com/android/server/NetworkTimeUpdateService.java
index 2c24798..b3a8fb6 100644
--- a/services/core/java/com/android/server/NetworkTimeUpdateService.java
+++ b/services/core/java/com/android/server/NetworkTimeUpdateService.java
@@ -23,7 +23,6 @@
 import android.content.Context;
 import android.content.Intent;
 import android.content.IntentFilter;
-import android.content.pm.PackageManager;
 import android.database.ContentObserver;
 import android.net.ConnectivityManager;
 import android.net.ConnectivityManager.NetworkCallback;
@@ -33,13 +32,12 @@
 import android.os.HandlerThread;
 import android.os.Looper;
 import android.os.Message;
-import android.os.SystemClock;
 import android.os.PowerManager;
+import android.os.SystemClock;
 import android.provider.Settings;
 import android.util.Log;
 import android.util.NtpTrustedTime;
 import android.util.TimeUtils;
-import android.util.TrustedTime;
 
 import com.android.internal.telephony.TelephonyIntents;
 import com.android.internal.util.DumpUtils;
@@ -75,19 +73,17 @@
     private long mNitzTimeSetTime = NOT_SET;
     private Network mDefaultNetwork = null;
 
-    private Context mContext;
-    private TrustedTime mTime;
+    private final Context mContext;
+    private final NtpTrustedTime mTime;
+    private final AlarmManager mAlarmManager;
+    private final ConnectivityManager mCM;
+    private final PendingIntent mPendingPollIntent;
+    private final PowerManager.WakeLock mWakeLock;
 
     // NTP lookup is done on this thread and handler
     private Handler mHandler;
-    private AlarmManager mAlarmManager;
-    private PendingIntent mPendingPollIntent;
     private SettingsObserver mSettingsObserver;
-    private ConnectivityManager mCM;
     private NetworkTimeUpdateCallback mNetworkTimeUpdateCallback;
-    // The last time that we successfully fetched the NTP time.
-    private long mLastNtpFetchTime = NOT_SET;
-    private final PowerManager.WakeLock mWakeLock;
 
     // Normal polling frequency
     private final long mPollingIntervalMs;
@@ -105,8 +101,9 @@
     public NetworkTimeUpdateService(Context context) {
         mContext = context;
         mTime = NtpTrustedTime.getInstance(context);
-        mAlarmManager = (AlarmManager) mContext.getSystemService(Context.ALARM_SERVICE);
-        mCM = (ConnectivityManager) mContext.getSystemService(Context.CONNECTIVITY_SERVICE);
+        mAlarmManager = mContext.getSystemService(AlarmManager.class);
+        mCM = mContext.getSystemService(ConnectivityManager.class);
+
         Intent pollIntent = new Intent(ACTION_POLL, null);
         mPendingPollIntent = PendingIntent.getBroadcast(mContext, POLL_REQUEST, pollIntent, 0);
 
@@ -119,7 +116,7 @@
         mTimeErrorThresholdMs = mContext.getResources().getInteger(
                 com.android.internal.R.integer.config_ntpThreshold);
 
-        mWakeLock = ((PowerManager) context.getSystemService(Context.POWER_SERVICE)).newWakeLock(
+        mWakeLock = context.getSystemService(PowerManager.class).newWakeLock(
                 PowerManager.PARTIAL_WAKE_LOCK, TAG);
     }
 
@@ -157,7 +154,7 @@
     private void onPollNetworkTime(int event) {
         // If Automatic time is not set, don't bother. Similarly, if we don't
         // have any default network, don't bother.
-        if (!isAutomaticTimeRequested() || mDefaultNetwork == null) return;
+        if (mDefaultNetwork == null) return;
         mWakeLock.acquire();
         try {
             onPollNetworkTimeUnderWakeLock(event);
@@ -167,61 +164,60 @@
     }
 
     private void onPollNetworkTimeUnderWakeLock(int event) {
-        final long refTime = SystemClock.elapsedRealtime();
-        // If NITZ time was received less than mPollingIntervalMs time ago,
-        // no need to sync to NTP.
-        if (mNitzTimeSetTime != NOT_SET && refTime - mNitzTimeSetTime < mPollingIntervalMs) {
-            resetAlarm(mPollingIntervalMs);
-            return;
+        // Force an NTP fix when outdated
+        if (mTime.getCacheAge() >= mPollingIntervalMs) {
+            if (DBG) Log.d(TAG, "Stale NTP fix; forcing refresh");
+            mTime.forceRefresh();
         }
-        final long currentTime = System.currentTimeMillis();
-        if (DBG) Log.d(TAG, "System time = " + currentTime);
-        // Get the NTP time
-        if (mLastNtpFetchTime == NOT_SET || refTime >= mLastNtpFetchTime + mPollingIntervalMs
-                || event == EVENT_AUTO_TIME_CHANGED) {
-            if (DBG) Log.d(TAG, "Before Ntp fetch");
 
-            // force refresh NTP cache when outdated
-            if (mTime.getCacheAge() >= mPollingIntervalMs) {
-                mTime.forceRefresh();
+        if (mTime.getCacheAge() < mPollingIntervalMs) {
+            // Obtained fresh fix; schedule next normal update
+            resetAlarm(mPollingIntervalMs);
+            if (isAutomaticTimeRequested()) {
+                updateSystemClock(event);
             }
 
-            // only update when NTP time is fresh
-            if (mTime.getCacheAge() < mPollingIntervalMs) {
-                final long ntp = mTime.currentTimeMillis();
-                mTryAgainCounter = 0;
-                // If the clock is more than N seconds off or this is the first time it's been
-                // fetched since boot, set the current time.
-                if (Math.abs(ntp - currentTime) > mTimeErrorThresholdMs
-                        || mLastNtpFetchTime == NOT_SET) {
-                    // Set the system time
-                    if (DBG && mLastNtpFetchTime == NOT_SET
-                            && Math.abs(ntp - currentTime) <= mTimeErrorThresholdMs) {
-                        Log.d(TAG, "For initial setup, rtc = " + currentTime);
-                    }
-                    if (DBG) Log.d(TAG, "Ntp time to be set = " + ntp);
-                    // Make sure we don't overflow, since it's going to be converted to an int
-                    if (ntp / 1000 < Integer.MAX_VALUE) {
-                        SystemClock.setCurrentTimeMillis(ntp);
-                    }
-                } else {
-                    if (DBG) Log.d(TAG, "Ntp time is close enough = " + ntp);
-                }
-                mLastNtpFetchTime = SystemClock.elapsedRealtime();
+        } else {
+            // No fresh fix; schedule retry
+            mTryAgainCounter++;
+            if (mTryAgainTimesMax < 0 || mTryAgainCounter <= mTryAgainTimesMax) {
+                resetAlarm(mPollingIntervalShorterMs);
             } else {
-                // Try again shortly
-                mTryAgainCounter++;
-                if (mTryAgainTimesMax < 0 || mTryAgainCounter <= mTryAgainTimesMax) {
-                    resetAlarm(mPollingIntervalShorterMs);
-                } else {
-                    // Try much later
-                    mTryAgainCounter = 0;
-                    resetAlarm(mPollingIntervalMs);
-                }
+                // Try much later
+                mTryAgainCounter = 0;
+                resetAlarm(mPollingIntervalMs);
+            }
+        }
+    }
+
+    private long getNitzAge() {
+        if (mNitzTimeSetTime == NOT_SET) {
+            return Long.MAX_VALUE;
+        } else {
+            return SystemClock.elapsedRealtime() - mNitzTimeSetTime;
+        }
+    }
+
+    /**
+     * Consider updating system clock based on current NTP fix, if requested by
+     * user, significant enough delta, and we don't have a recent NITZ.
+     */
+    private void updateSystemClock(int event) {
+        final boolean forceUpdate = (event == EVENT_AUTO_TIME_CHANGED);
+        if (!forceUpdate) {
+            if (getNitzAge() < mPollingIntervalMs) {
+                if (DBG) Log.d(TAG, "Ignoring NTP update due to recent NITZ");
+                return;
+            }
+
+            final long skew = Math.abs(mTime.currentTimeMillis() - System.currentTimeMillis());
+            if (skew < mTimeErrorThresholdMs) {
+                if (DBG) Log.d(TAG, "Ignoring NTP update due to low skew");
                 return;
             }
         }
-        resetAlarm(mPollingIntervalMs);
+
+        SystemClock.setCurrentTimeMillis(mTime.currentTimeMillis());
     }
 
     /**
@@ -326,8 +322,8 @@
         pw.print("TimeErrorThresholdMs: ");
         TimeUtils.formatDuration(mTimeErrorThresholdMs, pw);
         pw.println("\nTryAgainCounter: " + mTryAgainCounter);
-        pw.print("LastNtpFetchTime: ");
-        TimeUtils.formatDuration(mLastNtpFetchTime, pw);
+        pw.println("NTP cache age: " + mTime.getCacheAge());
+        pw.println("NTP cache certainty: " + mTime.getCacheCertainty());
         pw.println();
     }
 }
diff --git a/services/core/java/com/android/server/net/NetworkPolicyManagerService.java b/services/core/java/com/android/server/net/NetworkPolicyManagerService.java
index e2b2d46..bd9ec55 100644
--- a/services/core/java/com/android/server/net/NetworkPolicyManagerService.java
+++ b/services/core/java/com/android/server/net/NetworkPolicyManagerService.java
@@ -147,6 +147,7 @@
 import android.os.Binder;
 import android.os.Build;
 import android.os.Environment;
+import android.os.BestClock;
 import android.os.Handler;
 import android.os.HandlerThread;
 import android.os.IDeviceIdleController;
@@ -164,6 +165,7 @@
 import android.os.ResultReceiver;
 import android.os.ServiceManager;
 import android.os.ShellCallback;
+import android.os.SystemClock;
 import android.os.SystemProperties;
 import android.os.Trace;
 import android.os.UserHandle;
@@ -183,7 +185,6 @@
 import android.util.AtomicFile;
 import android.util.DataUnit;
 import android.util.Log;
-import android.util.NtpTrustedTime;
 import android.util.Pair;
 import android.util.RecurrenceRule;
 import android.util.Slog;
@@ -191,7 +192,6 @@
 import android.util.SparseBooleanArray;
 import android.util.SparseIntArray;
 import android.util.SparseLongArray;
-import android.util.TrustedTime;
 import android.util.Xml;
 
 import com.android.internal.R;
@@ -226,7 +226,9 @@
 import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
 import java.nio.charset.StandardCharsets;
+import java.time.Clock;
 import java.time.ZoneId;
+import java.time.ZoneOffset;
 import java.time.ZonedDateTime;
 import java.util.ArrayList;
 import java.util.Calendar;
@@ -335,8 +337,6 @@
     private static final String ACTION_SNOOZE_RAPID =
             "com.android.server.net.action.SNOOZE_RAPID";
 
-    private static final long TIME_CACHE_MAX_AGE = DAY_IN_MILLIS;
-
     /**
      * Indicates the maximum wait time for admin data to be available;
      */
@@ -362,7 +362,7 @@
     private final INetworkStatsService mNetworkStats;
     private final INetworkManagementService mNetworkManager;
     private UsageStatsManagerInternal mUsageStats;
-    private final TrustedTime mTime;
+    private final Clock mClock;
     private final UserManager mUserManager;
     private final CarrierConfigManager mCarrierConfigManager;
 
@@ -518,24 +518,29 @@
     public NetworkPolicyManagerService(Context context, IActivityManager activityManager,
             INetworkStatsService networkStats, INetworkManagementService networkManagement) {
         this(context, activityManager, networkStats, networkManagement,
-                AppGlobals.getPackageManager(), NtpTrustedTime.getInstance(context), getSystemDir(),
+                AppGlobals.getPackageManager(), getDefaultClock(), getDefaultSystemDir(),
                 false);
     }
 
-    private static File getSystemDir() {
+    private static @NonNull File getDefaultSystemDir() {
         return new File(Environment.getDataDirectory(), "system");
     }
 
+    private static @NonNull Clock getDefaultClock() {
+        return new BestClock(ZoneOffset.UTC, SystemClock.currentNetworkTimeClock(),
+                Clock.systemUTC());
+    }
+
     public NetworkPolicyManagerService(Context context, IActivityManager activityManager,
             INetworkStatsService networkStats, INetworkManagementService networkManagement,
-            IPackageManager pm, TrustedTime time, File systemDir, boolean suppressDefaultPolicy) {
+            IPackageManager pm, Clock clock, File systemDir, boolean suppressDefaultPolicy) {
         mContext = checkNotNull(context, "missing context");
         mActivityManager = checkNotNull(activityManager, "missing activityManager");
         mNetworkStats = checkNotNull(networkStats, "missing networkStats");
         mNetworkManager = checkNotNull(networkManagement, "missing networkManagement");
         mDeviceIdleController = IDeviceIdleController.Stub.asInterface(ServiceManager.getService(
                 Context.DEVICE_IDLE_CONTROLLER));
-        mTime = checkNotNull(time, "missing TrustedTime");
+        mClock = checkNotNull(clock, "missing Clock");
         mUserManager = (UserManager) mContext.getSystemService(Context.USER_SERVICE);
         mCarrierConfigManager = mContext.getSystemService(CarrierConfigManager.class);
         mIPm = pm;
@@ -932,7 +937,6 @@
             // on background handler thread, and verified
             // READ_NETWORK_USAGE_HISTORY permission above.
 
-            maybeRefreshTrustedTime();
             synchronized (mNetworkPoliciesSecondLock) {
                 updateNetworkEnabledNL();
                 updateNotificationsNL();
@@ -1042,7 +1046,7 @@
         // cycle boundary to recompute notifications.
 
         // examine stats for each active policy
-        final long now = currentTimeMillis();
+        final long now = mClock.millis();
         for (int i = mNetworkPolicy.size()-1; i >= 0; i--) {
             final NetworkPolicy policy = mNetworkPolicy.valueAt(i);
             // ignore policies that aren't relevant to user
@@ -1299,7 +1303,6 @@
             // on background handler thread, and verified CONNECTIVITY_INTERNAL
             // permission above.
 
-            maybeRefreshTrustedTime();
             synchronized (mUidRulesFirstLock) {
                 synchronized (mNetworkPoliciesSecondLock) {
                     ensureActiveMobilePolicyAL();
@@ -1462,7 +1465,6 @@
             final TelephonyManager tele = mContext.getSystemService(TelephonyManager.class);
             final String subscriberId = tele.getSubscriberId(subId);
 
-            maybeRefreshTrustedTime();
             synchronized (mUidRulesFirstLock) {
                 synchronized (mNetworkPoliciesSecondLock) {
                     final boolean added = ensureActiveMobilePolicyAL(subId, subscriberId);
@@ -1723,7 +1725,7 @@
                 final long totalBytes = getTotalBytes(
                         NetworkTemplate.buildTemplateMobileAll(state.subscriberId), start, end);
                 final long remainingBytes = limitBytes - totalBytes;
-                final long remainingDays = Math.max(1, (end - currentTimeMillis())
+                final long remainingDays = Math.max(1, (end - mClock.millis())
                         / TimeUnit.DAYS.toMillis(1));
                 if (remainingBytes > 0) {
                     quotaBytes = (remainingBytes / remainingDays) / 10;
@@ -2444,7 +2446,6 @@
 
         final long token = Binder.clearCallingIdentity();
         try {
-            maybeRefreshTrustedTime();
             synchronized (mUidRulesFirstLock) {
                 synchronized (mNetworkPoliciesSecondLock) {
                     normalizePoliciesNL(policies);
@@ -2524,8 +2525,7 @@
     }
 
     void performSnooze(NetworkTemplate template, int type) {
-        maybeRefreshTrustedTime();
-        final long currentTime = currentTimeMillis();
+        final long currentTime = mClock.millis();
         synchronized (mUidRulesFirstLock) {
             synchronized (mNetworkPoliciesSecondLock) {
                 // find and snooze local policy that matches
@@ -2571,7 +2571,6 @@
             mContext.enforceCallingOrSelfPermission(MANAGE_NETWORK_POLICY, TAG);
             final long token = Binder.clearCallingIdentity();
             try {
-                maybeRefreshTrustedTime();
                 synchronized (mUidRulesFirstLock) {
                     setRestrictBackgroundUL(restrictBackground);
                 }
@@ -2916,7 +2915,6 @@
 
         final long token = Binder.clearCallingIdentity();
         try {
-            maybeRefreshTrustedTime();
             synchronized (mUidRulesFirstLock) {
                 synchronized (mNetworkPoliciesSecondLock) {
                     mSubscriptionPlans.put(subId, plans);
@@ -4028,7 +4026,6 @@
                 case MSG_LIMIT_REACHED: {
                     final String iface = (String) msg.obj;
 
-                    maybeRefreshTrustedTime();
                     synchronized (mNetworkPoliciesSecondLock) {
                         if (mMeteredIfaces.contains(iface)) {
                             try {
@@ -4393,19 +4390,6 @@
         }
     }
 
-    /**
-     * Try refreshing {@link #mTime} when stale.
-     */
-    void maybeRefreshTrustedTime() {
-        if (mTime.getCacheAge() > TIME_CACHE_MAX_AGE) {
-            mTime.forceRefresh();
-        }
-    }
-
-    private long currentTimeMillis() {
-        return mTime.hasCache() ? mTime.currentTimeMillis() : System.currentTimeMillis();
-    }
-
     private static Intent buildAllowBackgroundDataIntent() {
         return new Intent(ACTION_ALLOW_BACKGROUND);
     }
diff --git a/services/core/java/com/android/server/net/NetworkStatsService.java b/services/core/java/com/android/server/net/NetworkStatsService.java
index 76c4db1..d1aa212 100644
--- a/services/core/java/com/android/server/net/NetworkStatsService.java
+++ b/services/core/java/com/android/server/net/NetworkStatsService.java
@@ -68,6 +68,7 @@
 import static com.android.server.NetworkManagementSocketTagger.resetKernelUidStats;
 import static com.android.server.NetworkManagementSocketTagger.setKernelCounterSet;
 
+import android.annotation.NonNull;
 import android.app.AlarmManager;
 import android.app.PendingIntent;
 import android.app.usage.NetworkStatsManager;
@@ -97,6 +98,7 @@
 import android.os.Binder;
 import android.os.DropBoxManager;
 import android.os.Environment;
+import android.os.BestClock;
 import android.os.Handler;
 import android.os.HandlerThread;
 import android.os.IBinder;
@@ -120,10 +122,8 @@
 import android.util.EventLog;
 import android.util.Log;
 import android.util.MathUtils;
-import android.util.NtpTrustedTime;
 import android.util.Slog;
 import android.util.SparseIntArray;
-import android.util.TrustedTime;
 import android.util.proto.ProtoOutputStream;
 
 import com.android.internal.annotations.GuardedBy;
@@ -140,6 +140,8 @@
 import java.io.FileDescriptor;
 import java.io.IOException;
 import java.io.PrintWriter;
+import java.time.Clock;
+import java.time.ZoneOffset;
 import java.util.Arrays;
 import java.util.HashSet;
 import java.util.List;
@@ -167,7 +169,7 @@
     private final Context mContext;
     private final INetworkManagementService mNetworkManager;
     private final AlarmManager mAlarmManager;
-    private final TrustedTime mTime;
+    private final Clock mClock;
     private final TelephonyManager mTeleManager;
     private final NetworkStatsSettings mSettings;
     private final NetworkStatsObservers mStatsObservers;
@@ -202,7 +204,6 @@
      */
     public interface NetworkStatsSettings {
         public long getPollInterval();
-        public long getTimeCacheMaxAge();
         public boolean getSampleEnabled();
         public boolean getAugmentEnabled();
 
@@ -281,16 +282,21 @@
     private long mPersistThreshold = 2 * MB_IN_BYTES;
     private long mGlobalAlertBytes;
 
-    private static File getDefaultSystemDir() {
+    private static @NonNull File getDefaultSystemDir() {
         return new File(Environment.getDataDirectory(), "system");
     }
 
-    private static File getDefaultBaseDir() {
+    private static @NonNull File getDefaultBaseDir() {
         File baseDir = new File(getDefaultSystemDir(), "netstats");
         baseDir.mkdirs();
         return baseDir;
     }
 
+    private static @NonNull Clock getDefaultClock() {
+        return new BestClock(ZoneOffset.UTC, SystemClock.currentNetworkTimeClock(),
+                Clock.systemUTC());
+    }
+
     public static NetworkStatsService create(Context context,
                 INetworkManagementService networkManager) {
         AlarmManager alarmManager = (AlarmManager) context.getSystemService(Context.ALARM_SERVICE);
@@ -299,7 +305,7 @@
                 powerManager.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK, TAG);
 
         NetworkStatsService service = new NetworkStatsService(context, networkManager, alarmManager,
-                wakeLock, NtpTrustedTime.getInstance(context), TelephonyManager.getDefault(),
+                wakeLock, getDefaultClock(), TelephonyManager.getDefault(),
                 new DefaultNetworkStatsSettings(context), new NetworkStatsObservers(),
                 getDefaultSystemDir(), getDefaultBaseDir());
 
@@ -313,13 +319,13 @@
 
     @VisibleForTesting
     NetworkStatsService(Context context, INetworkManagementService networkManager,
-            AlarmManager alarmManager, PowerManager.WakeLock wakeLock, TrustedTime time,
+            AlarmManager alarmManager, PowerManager.WakeLock wakeLock, Clock clock,
             TelephonyManager teleManager, NetworkStatsSettings settings,
             NetworkStatsObservers statsObservers, File systemDir, File baseDir) {
         mContext = checkNotNull(context, "missing Context");
         mNetworkManager = checkNotNull(networkManager, "missing INetworkManagementService");
         mAlarmManager = checkNotNull(alarmManager, "missing AlarmManager");
-        mTime = checkNotNull(time, "missing TrustedTime");
+        mClock = checkNotNull(clock, "missing Clock");
         mSettings = checkNotNull(settings, "missing NetworkStatsSettings");
         mTeleManager = checkNotNull(teleManager, "missing TelephonyManager");
         mWakeLock = checkNotNull(wakeLock, "missing WakeLock");
@@ -413,8 +419,7 @@
         mContext.unregisterReceiver(mUserReceiver);
         mContext.unregisterReceiver(mShutdownReceiver);
 
-        final long currentTime = mTime.hasCache() ? mTime.currentTimeMillis()
-                : System.currentTimeMillis();
+        final long currentTime = mClock.millis();
 
         // persist any pending stats
         mDevRecorder.forcePersistLocked(currentTime);
@@ -831,8 +836,7 @@
         }
 
         // update and persist if beyond new thresholds
-        final long currentTime = mTime.hasCache() ? mTime.currentTimeMillis()
-                : System.currentTimeMillis();
+        final long currentTime = mClock.millis();
         synchronized (mStatsLock) {
             if (!mSystemReady) return;
 
@@ -1170,8 +1174,7 @@
      */
     @GuardedBy("mStatsLock")
     private void bootstrapStatsLocked() {
-        final long currentTime = mTime.hasCache() ? mTime.currentTimeMillis()
-                : System.currentTimeMillis();
+        final long currentTime = mClock.millis();
 
         try {
             recordSnapshotLocked(currentTime);
@@ -1183,11 +1186,6 @@
     }
 
     private void performPoll(int flags) {
-        // try refreshing time source when stale
-        if (mTime.getCacheAge() > mSettings.getTimeCacheMaxAge()) {
-            mTime.forceRefresh();
-        }
-
         synchronized (mStatsLock) {
             mWakeLock.acquire();
 
@@ -1215,8 +1213,7 @@
         final boolean persistForce = (flags & FLAG_PERSIST_FORCE) != 0;
 
         // TODO: consider marking "untrusted" times in historical stats
-        final long currentTime = mTime.hasCache() ? mTime.currentTimeMillis()
-                : System.currentTimeMillis();
+        final long currentTime = mClock.millis();
 
         try {
             recordSnapshotLocked(currentTime);
@@ -1268,7 +1265,7 @@
     @GuardedBy("mStatsLock")
     private void performSampleLocked() {
         // TODO: migrate trustedtime fixes to separate binary log events
-        final long trustedTime = mTime.hasCache() ? mTime.currentTimeMillis() : -1;
+        final long currentTime = mClock.millis();
 
         NetworkTemplate template;
         NetworkStats.Entry devTotal;
@@ -1285,7 +1282,7 @@
                 devTotal.rxBytes, devTotal.rxPackets, devTotal.txBytes, devTotal.txPackets,
                 xtTotal.rxBytes, xtTotal.rxPackets, xtTotal.txBytes, xtTotal.txPackets,
                 uidTotal.rxBytes, uidTotal.rxPackets, uidTotal.txBytes, uidTotal.txPackets,
-                trustedTime);
+                currentTime);
 
         // collect wifi sample
         template = buildTemplateWifiWildcard();
@@ -1297,7 +1294,7 @@
                 devTotal.rxBytes, devTotal.rxPackets, devTotal.txBytes, devTotal.txPackets,
                 xtTotal.rxBytes, xtTotal.rxPackets, xtTotal.txBytes, xtTotal.txPackets,
                 uidTotal.rxBytes, uidTotal.rxPackets, uidTotal.txBytes, uidTotal.txPackets,
-                trustedTime);
+                currentTime);
     }
 
     /**
@@ -1621,10 +1618,6 @@
             return getGlobalLong(NETSTATS_POLL_INTERVAL, 30 * MINUTE_IN_MILLIS);
         }
         @Override
-        public long getTimeCacheMaxAge() {
-            return getGlobalLong(NETSTATS_TIME_CACHE_MAX_AGE, DAY_IN_MILLIS);
-        }
-        @Override
         public long getGlobalAlertBytes(long def) {
             return getGlobalLong(NETSTATS_GLOBAL_ALERT_BYTES, def);
         }
diff --git a/services/tests/servicestests/src/com/android/server/NetworkPolicyManagerServiceTest.java b/services/tests/servicestests/src/com/android/server/NetworkPolicyManagerServiceTest.java
index 184e8de..e1b4422 100644
--- a/services/tests/servicestests/src/com/android/server/NetworkPolicyManagerServiceTest.java
+++ b/services/tests/servicestests/src/com/android/server/NetworkPolicyManagerServiceTest.java
@@ -104,6 +104,7 @@
 import android.os.PowerManagerInternal;
 import android.os.PowerSaveState;
 import android.os.RemoteException;
+import android.os.SimpleClock;
 import android.os.UserHandle;
 import android.support.test.InstrumentationRegistry;
 import android.support.test.runner.AndroidJUnit4;
@@ -118,7 +119,6 @@
 import android.util.Log;
 import android.util.Pair;
 import android.util.RecurrenceRule;
-import android.util.TrustedTime;
 
 import com.android.internal.telephony.PhoneConstants;
 import com.android.internal.util.test.BroadcastInterceptingContext;
@@ -158,6 +158,7 @@
 import java.time.Instant;
 import java.time.Period;
 import java.time.ZoneId;
+import java.time.ZoneOffset;
 import java.time.ZonedDateTime;
 import java.util.Arrays;
 import java.util.Calendar;
@@ -215,7 +216,6 @@
     private @Mock IActivityManager mActivityManager;
     private @Mock INetworkStatsService mStatsService;
     private @Mock INetworkManagementService mNetworkManager;
-    private @Mock TrustedTime mTime;
     private @Mock IConnectivityManager mConnManager;
     private @Mock NotificationManager mNotifManager;
     private @Mock PackageManager mPackageManager;
@@ -267,6 +267,13 @@
 
     public final @Rule NetPolicyMethodRule mNetPolicyXmlRule = new NetPolicyMethodRule();
 
+    private final Clock mClock = new SimpleClock(ZoneOffset.UTC) {
+        @Override
+        public long millis() {
+            return currentTimeMillis();
+        }
+    };
+
     private void registerLocalServices() {
         addLocalServiceMock(DeviceIdleController.LocalService.class);
 
@@ -341,7 +348,7 @@
 
         mFutureIntent = newRestrictBackgroundChangedFuture();
         mService = new NetworkPolicyManagerService(mServiceContext, mActivityManager, mStatsService,
-                mNetworkManager, mIpm, mTime, mPolicyDir, true);
+                mNetworkManager, mIpm, mClock, mPolicyDir, true);
         mService.bindConnectivityManager(mConnManager);
         mPolicyListener = new NetworkPolicyListenerAnswer(mService);
 
@@ -370,7 +377,6 @@
         when(mPackageManager.getPackagesForUid(UID_A)).thenReturn(new String[] {PKG_NAME_A});
         when(mNetworkManager.isBandwidthControlEnabled()).thenReturn(true);
         when(mNetworkManager.setDataSaverModeEnabled(anyBoolean())).thenReturn(true);
-        expectCurrentTime();
 
         // Prepare NPMS.
         mService.systemReady(mService.networkScoreAndNetworkManagementServiceReady());
@@ -940,7 +946,6 @@
         // which means we shouldn't push limit to interface.
         state = new NetworkState[] { buildWifi() };
         when(mConnManager.getAllNetworkState()).thenReturn(state);
-        expectCurrentTime();
 
         mPolicyListener.expect().onMeteredIfacesChanged(any());
         mServiceContext.sendBroadcast(new Intent(CONNECTIVITY_ACTION));
@@ -949,7 +954,6 @@
         // now change cycle to be on 15th, and test in early march, to verify we
         // pick cycle day in previous month.
         when(mConnManager.getAllNetworkState()).thenReturn(state);
-        expectCurrentTime();
 
         // pretend that 512 bytes total have happened
         stats = new NetworkStats(getElapsedRealtime(), 1)
@@ -996,7 +1000,6 @@
         final long start = parseTime("2015-11-01T00:00Z");
         final long end = parseTime("2015-11-07T00:00Z");
         setCurrentTimeMillis(end);
-        expectCurrentTime();
 
         // Normal usage means no notification
         {
@@ -1096,7 +1099,6 @@
         final long start = parseTime("2015-11-01T00:00Z");
         final long end = parseTime("2015-11-07T00:00Z");
         setCurrentTimeMillis(end);
-        expectCurrentTime();
 
         // Using 20% data in 20% time is normal
         {
@@ -1139,7 +1141,6 @@
                 .addIfaceValues(TEST_IFACE, 0L, 0L, 0L, 0L);
 
         {
-            expectCurrentTime();
             when(mConnManager.getAllNetworkState()).thenReturn(state);
             when(mStatsService.getNetworkTotalBytes(sTemplateWifi, TIME_FEB_15,
                     currentTimeMillis())).thenReturn(stats.getTotalBytes());
@@ -1474,14 +1475,6 @@
         return new NetworkState(info, prop, networkCapabilities, null, null, TEST_SSID);
     }
 
-    private void expectCurrentTime() throws Exception {
-        when(mTime.forceRefresh()).thenReturn(false);
-        when(mTime.hasCache()).thenReturn(true);
-        when(mTime.currentTimeMillis()).thenReturn(currentTimeMillis());
-        when(mTime.getCacheAge()).thenReturn(0L);
-        when(mTime.getCacheCertainty()).thenReturn(0L);
-    }
-
     private void expectHasInternetPermission(int uid, boolean hasIt) throws Exception {
         when(mIpm.checkUidPermission(Manifest.permission.INTERNET, uid)).thenReturn(
                 hasIt ? PackageManager.PERMISSION_GRANTED : PackageManager.PERMISSION_DENIED);
diff --git a/tests/net/java/com/android/server/net/NetworkStatsServiceTest.java b/tests/net/java/com/android/server/net/NetworkStatsServiceTest.java
index 0f26edb..b1b05e8 100644
--- a/tests/net/java/com/android/server/net/NetworkStatsServiceTest.java
+++ b/tests/net/java/com/android/server/net/NetworkStatsServiceTest.java
@@ -87,12 +87,11 @@
 import android.os.Message;
 import android.os.Messenger;
 import android.os.PowerManager;
+import android.os.SimpleClock;
 import android.support.test.InstrumentationRegistry;
-import android.support.test.runner.AndroidJUnit4;
 import android.support.test.filters.SmallTest;
+import android.support.test.runner.AndroidJUnit4;
 import android.telephony.TelephonyManager;
-import android.util.Log;
-import android.util.TrustedTime;
 
 import com.android.internal.net.VpnInfo;
 import com.android.internal.util.test.BroadcastInterceptingContext;
@@ -111,6 +110,8 @@
 import org.mockito.MockitoAnnotations;
 
 import java.io.File;
+import java.time.Clock;
+import java.time.ZoneOffset;
 import java.util.Objects;
 
 /**
@@ -155,7 +156,6 @@
     private File mStatsDir;
 
     private @Mock INetworkManagementService mNetManager;
-    private @Mock TrustedTime mTime;
     private @Mock NetworkStatsSettings mSettings;
     private @Mock IConnectivityManager mConnManager;
     private @Mock IBinder mBinder;
@@ -167,6 +167,13 @@
     private INetworkStatsSession mSession;
     private INetworkManagementEventObserver mNetworkObserver;
 
+    private final Clock mClock = new SimpleClock(ZoneOffset.UTC) {
+        @Override
+        public long millis() {
+            return currentTimeMillis();
+        }
+    };
+
     @Before
     public void setUp() throws Exception {
         MockitoAnnotations.initMocks(this);
@@ -184,7 +191,7 @@
                 powerManager.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK, TAG);
 
         mService = new NetworkStatsService(
-                mServiceContext, mNetManager, mAlarmManager, wakeLock, mTime,
+                mServiceContext, mNetManager, mAlarmManager, wakeLock, mClock,
                 TelephonyManager.getDefault(), mSettings, new NetworkStatsObservers(),
                 mStatsDir, getBaseDir(mStatsDir));
         mHandlerThread = new HandlerThread("HandlerThread");
@@ -196,7 +203,6 @@
 
         mElapsedRealtime = 0L;
 
-        expectCurrentTime();
         expectDefaultSettings();
         expectNetworkStatsUidDetail(buildEmptyStats());
         expectSystemReady();
@@ -221,7 +227,6 @@
         mStatsDir = null;
 
         mNetManager = null;
-        mTime = null;
         mSettings = null;
         mConnManager = null;
 
@@ -233,7 +238,6 @@
     public void testNetworkStatsWifi() throws Exception {
         // pretend that wifi network comes online; service should ask about full
         // network state, and poll any existing interfaces before updating.
-        expectCurrentTime();
         expectDefaultSettings();
         expectNetworkState(buildWifiState());
         expectNetworkStatsSummary(buildEmptyStats());
@@ -248,7 +252,6 @@
 
         // modify some number on wifi, and trigger poll event
         incrementCurrentTime(HOUR_IN_MILLIS);
-        expectCurrentTime();
         expectDefaultSettings();
         expectNetworkStatsSummary(new NetworkStats(getElapsedRealtime(), 1)
                 .addIfaceValues(TEST_IFACE, 1024L, 1L, 2048L, 2L));
@@ -262,7 +265,6 @@
         // and bump forward again, with counters going higher. this is
         // important, since polling should correctly subtract last snapshot.
         incrementCurrentTime(DAY_IN_MILLIS);
-        expectCurrentTime();
         expectDefaultSettings();
         expectNetworkStatsSummary(new NetworkStats(getElapsedRealtime(), 1)
                 .addIfaceValues(TEST_IFACE, 4096L, 4L, 8192L, 8L));
@@ -280,7 +282,6 @@
 
         // pretend that wifi network comes online; service should ask about full
         // network state, and poll any existing interfaces before updating.
-        expectCurrentTime();
         expectDefaultSettings();
         expectNetworkState(buildWifiState());
         expectNetworkStatsSummary(buildEmptyStats());
@@ -295,7 +296,6 @@
 
         // modify some number on wifi, and trigger poll event
         incrementCurrentTime(HOUR_IN_MILLIS);
-        expectCurrentTime();
         expectDefaultSettings();
         expectNetworkStatsSummary(new NetworkStats(getElapsedRealtime(), 1)
                 .addIfaceValues(TEST_IFACE, 1024L, 8L, 2048L, 16L));
@@ -324,13 +324,11 @@
 
         // graceful shutdown system, which should trigger persist of stats, and
         // clear any values in memory.
-        expectCurrentTime();
         expectDefaultSettings();
         mServiceContext.sendBroadcast(new Intent(Intent.ACTION_SHUTDOWN));
         assertStatsFilesExist(true);
 
         // boot through serviceReady() again
-        expectCurrentTime();
         expectDefaultSettings();
         expectNetworkStatsUidDetail(buildEmptyStats());
         expectSystemReady();
@@ -358,7 +356,6 @@
 
         // pretend that wifi network comes online; service should ask about full
         // network state, and poll any existing interfaces before updating.
-        expectCurrentTime();
         expectSettings(0L, HOUR_IN_MILLIS, WEEK_IN_MILLIS);
         expectNetworkState(buildWifiState());
         expectNetworkStatsSummary(buildEmptyStats());
@@ -370,7 +367,6 @@
 
         // modify some number on wifi, and trigger poll event
         incrementCurrentTime(2 * HOUR_IN_MILLIS);
-        expectCurrentTime();
         expectSettings(0L, HOUR_IN_MILLIS, WEEK_IN_MILLIS);
         expectNetworkStatsSummary(new NetworkStats(getElapsedRealtime(), 1)
                 .addIfaceValues(TEST_IFACE, 512L, 4L, 512L, 4L));
@@ -386,7 +382,6 @@
 
         // now change bucket duration setting and trigger another poll with
         // exact same values, which should resize existing buckets.
-        expectCurrentTime();
         expectSettings(0L, 30 * MINUTE_IN_MILLIS, WEEK_IN_MILLIS);
         expectNetworkStatsSummary(buildEmptyStats());
         expectNetworkStatsUidDetail(buildEmptyStats());
@@ -403,7 +398,6 @@
     @Test
     public void testUidStatsAcrossNetworks() throws Exception {
         // pretend first mobile network comes online
-        expectCurrentTime();
         expectDefaultSettings();
         expectNetworkState(buildMobile3gState(IMSI_1));
         expectNetworkStatsSummary(buildEmptyStats());
@@ -415,7 +409,6 @@
 
         // create some traffic on first network
         incrementCurrentTime(HOUR_IN_MILLIS);
-        expectCurrentTime();
         expectDefaultSettings();
         expectNetworkStatsSummary(new NetworkStats(getElapsedRealtime(), 1)
                 .addIfaceValues(TEST_IFACE, 2048L, 16L, 512L, 4L));
@@ -437,7 +430,6 @@
         // now switch networks; this also tests that we're okay with interfaces
         // disappearing, to verify we don't count backwards.
         incrementCurrentTime(HOUR_IN_MILLIS);
-        expectCurrentTime();
         expectDefaultSettings();
         expectNetworkState(buildMobile3gState(IMSI_2));
         expectNetworkStatsSummary(new NetworkStats(getElapsedRealtime(), 1)
@@ -454,7 +446,6 @@
 
         // create traffic on second network
         incrementCurrentTime(HOUR_IN_MILLIS);
-        expectCurrentTime();
         expectDefaultSettings();
         expectNetworkStatsSummary(new NetworkStats(getElapsedRealtime(), 1)
                 .addIfaceValues(TEST_IFACE, 2176L, 17L, 1536L, 12L));
@@ -483,7 +474,6 @@
     @Test
     public void testUidRemovedIsMoved() throws Exception {
         // pretend that network comes online
-        expectCurrentTime();
         expectDefaultSettings();
         expectNetworkState(buildWifiState());
         expectNetworkStatsSummary(buildEmptyStats());
@@ -495,7 +485,6 @@
 
         // create some traffic
         incrementCurrentTime(HOUR_IN_MILLIS);
-        expectCurrentTime();
         expectDefaultSettings();
         expectNetworkStatsSummary(new NetworkStats(getElapsedRealtime(), 1)
                 .addIfaceValues(TEST_IFACE, 4128L, 258L, 544L, 34L));
@@ -517,7 +506,6 @@
 
         // now pretend two UIDs are uninstalled, which should migrate stats to
         // special "removed" bucket.
-        expectCurrentTime();
         expectDefaultSettings();
         expectNetworkStatsSummary(new NetworkStats(getElapsedRealtime(), 1)
                 .addIfaceValues(TEST_IFACE, 4128L, 258L, 544L, 34L));
@@ -545,7 +533,6 @@
     @Test
     public void testUid3g4gCombinedByTemplate() throws Exception {
         // pretend that network comes online
-        expectCurrentTime();
         expectDefaultSettings();
         expectNetworkState(buildMobile3gState(IMSI_1));
         expectNetworkStatsSummary(buildEmptyStats());
@@ -557,7 +544,6 @@
 
         // create some traffic
         incrementCurrentTime(HOUR_IN_MILLIS);
-        expectCurrentTime();
         expectDefaultSettings();
         expectNetworkStatsSummary(buildEmptyStats());
         expectNetworkStatsUidDetail(new NetworkStats(getElapsedRealtime(), 1)
@@ -573,7 +559,6 @@
 
         // now switch over to 4g network
         incrementCurrentTime(HOUR_IN_MILLIS);
-        expectCurrentTime();
         expectDefaultSettings();
         expectNetworkState(buildMobile4gState(TEST_IFACE2));
         expectNetworkStatsSummary(buildEmptyStats());
@@ -588,7 +573,6 @@
 
         // create traffic on second network
         incrementCurrentTime(HOUR_IN_MILLIS);
-        expectCurrentTime();
         expectDefaultSettings();
         expectNetworkStatsSummary(buildEmptyStats());
         expectNetworkStatsUidDetail(new NetworkStats(getElapsedRealtime(), 1)
@@ -607,7 +591,6 @@
     @Test
     public void testSummaryForAllUid() throws Exception {
         // pretend that network comes online
-        expectCurrentTime();
         expectDefaultSettings();
         expectNetworkState(buildWifiState());
         expectNetworkStatsSummary(buildEmptyStats());
@@ -619,7 +602,6 @@
 
         // create some traffic for two apps
         incrementCurrentTime(HOUR_IN_MILLIS);
-        expectCurrentTime();
         expectDefaultSettings();
         expectNetworkStatsSummary(buildEmptyStats());
         expectNetworkStatsUidDetail(new NetworkStats(getElapsedRealtime(), 1)
@@ -637,7 +619,6 @@
 
         // now create more traffic in next hour, but only for one app
         incrementCurrentTime(HOUR_IN_MILLIS);
-        expectCurrentTime();
         expectDefaultSettings();
         expectNetworkStatsSummary(buildEmptyStats());
         expectNetworkStatsUidDetail(new NetworkStats(getElapsedRealtime(), 1)
@@ -669,7 +650,6 @@
     @Test
     public void testForegroundBackground() throws Exception {
         // pretend that network comes online
-        expectCurrentTime();
         expectDefaultSettings();
         expectNetworkState(buildWifiState());
         expectNetworkStatsSummary(buildEmptyStats());
@@ -681,7 +661,6 @@
 
         // create some initial traffic
         incrementCurrentTime(HOUR_IN_MILLIS);
-        expectCurrentTime();
         expectDefaultSettings();
         expectNetworkStatsSummary(buildEmptyStats());
         expectNetworkStatsUidDetail(new NetworkStats(getElapsedRealtime(), 1)
@@ -697,7 +676,6 @@
 
         // now switch to foreground
         incrementCurrentTime(HOUR_IN_MILLIS);
-        expectCurrentTime();
         expectDefaultSettings();
         expectNetworkStatsSummary(buildEmptyStats());
         expectNetworkStatsUidDetail(new NetworkStats(getElapsedRealtime(), 1)
@@ -730,7 +708,6 @@
     @Test
     public void testMetered() throws Exception {
         // pretend that network comes online
-        expectCurrentTime();
         expectDefaultSettings();
         expectNetworkState(buildWifiState(true /* isMetered */));
         expectNetworkStatsSummary(buildEmptyStats());
@@ -742,7 +719,6 @@
 
         // create some initial traffic
         incrementCurrentTime(HOUR_IN_MILLIS);
-        expectCurrentTime();
         expectDefaultSettings();
         expectNetworkStatsSummary(buildEmptyStats());
         // Note that all traffic from NetworkManagementService is tagged as METERED_NO, ROAMING_NO
@@ -772,7 +748,6 @@
     @Test
     public void testRoaming() throws Exception {
         // pretend that network comes online
-        expectCurrentTime();
         expectDefaultSettings();
         expectNetworkState(buildMobile3gState(IMSI_1, true /* isRoaming */));
         expectNetworkStatsSummary(buildEmptyStats());
@@ -784,7 +759,6 @@
 
         // Create some traffic
         incrementCurrentTime(HOUR_IN_MILLIS);
-        expectCurrentTime();
         expectDefaultSettings();
         expectNetworkStatsSummary(buildEmptyStats());
         // Note that all traffic from NetworkManagementService is tagged as METERED_NO and
@@ -813,7 +787,6 @@
     @Test
     public void testTethering() throws Exception {
         // pretend first mobile network comes online
-        expectCurrentTime();
         expectDefaultSettings();
         expectNetworkState(buildMobile3gState(IMSI_1));
         expectNetworkStatsSummary(buildEmptyStats());
@@ -825,7 +798,6 @@
 
         // create some tethering traffic
         incrementCurrentTime(HOUR_IN_MILLIS);
-        expectCurrentTime();
         expectDefaultSettings();
 
         // Traffic seen by kernel counters (includes software tethering).
@@ -858,7 +830,6 @@
     public void testRegisterUsageCallback() throws Exception {
         // pretend that wifi network comes online; service should ask about full
         // network state, and poll any existing interfaces before updating.
-        expectCurrentTime();
         expectDefaultSettings();
         expectNetworkState(buildWifiState());
         expectNetworkStatsSummary(buildEmptyStats());
@@ -880,7 +851,6 @@
         Messenger messenger = new Messenger(latchedHandler);
 
         // Force poll
-        expectCurrentTime();
         expectDefaultSettings();
         expectNetworkStatsSummary(buildEmptyStats());
         expectNetworkStatsUidDetail(buildEmptyStats());
@@ -909,7 +879,6 @@
         // modify some number on wifi, and trigger poll event
         // not enough traffic to call data usage callback
         incrementCurrentTime(HOUR_IN_MILLIS);
-        expectCurrentTime();
         expectDefaultSettings();
         expectNetworkStatsSummary(new NetworkStats(getElapsedRealtime(), 1)
                 .addIfaceValues(TEST_IFACE, 1024L, 1L, 2048L, 2L));
@@ -925,7 +894,6 @@
         // and bump forward again, with counters going higher. this is
         // important, since it will trigger the data usage callback
         incrementCurrentTime(DAY_IN_MILLIS);
-        expectCurrentTime();
         expectDefaultSettings();
         expectNetworkStatsSummary(new NetworkStats(getElapsedRealtime(), 1)
                 .addIfaceValues(TEST_IFACE, 4096000L, 4L, 8192000L, 8L));
@@ -1068,7 +1036,6 @@
     private void expectSettings(long persistBytes, long bucketDuration, long deleteAge)
             throws Exception {
         when(mSettings.getPollInterval()).thenReturn(HOUR_IN_MILLIS);
-        when(mSettings.getTimeCacheMaxAge()).thenReturn(DAY_IN_MILLIS);
         when(mSettings.getSampleEnabled()).thenReturn(true);
 
         final Config config = new Config(bucketDuration, deleteAge, deleteAge);
@@ -1084,14 +1051,6 @@
         when(mSettings.getUidTagPersistBytes(anyLong())).thenReturn(MB_IN_BYTES);
     }
 
-    private void expectCurrentTime() throws Exception {
-        when(mTime.forceRefresh()).thenReturn(false);
-        when(mTime.hasCache()).thenReturn(true);
-        when(mTime.currentTimeMillis()).thenReturn(currentTimeMillis());
-        when(mTime.getCacheAge()).thenReturn(0L);
-        when(mTime.getCacheCertainty()).thenReturn(0L);
-    }
-
     private void expectBandwidthControlCheck() throws Exception {
         when(mNetManager.isBandwidthControlEnabled()).thenReturn(true);
     }