diff --git a/common/constants.cc b/common/constants.cc
index 2edfbb7..26adbe0 100644
--- a/common/constants.cc
+++ b/common/constants.cc
@@ -90,6 +90,7 @@
 const char kPrefsUpdateStateSignatureBlob[] = "update-state-signature-blob";
 const char kPrefsUpdateStateSignedSHA256Context[] =
     "update-state-signed-sha-256-context";
+const char kPrefsUpdateBootTimestampStart[] = "update-boot-timestamp-start";
 const char kPrefsUpdateTimestampStart[] = "update-timestamp-start";
 const char kPrefsUrlSwitchCount[] = "url-switch-count";
 const char kPrefsWallClockScatteringWaitPeriod[] = "wall-clock-wait-period";
diff --git a/common/constants.h b/common/constants.h
index d97c5fb..897d2e2 100644
--- a/common/constants.h
+++ b/common/constants.h
@@ -88,6 +88,7 @@
 extern const char kPrefsUpdateStateSHA256Context[];
 extern const char kPrefsUpdateStateSignatureBlob[];
 extern const char kPrefsUpdateStateSignedSHA256Context[];
+extern const char kPrefsUpdateBootTimestampStart[];
 extern const char kPrefsUpdateTimestampStart[];
 extern const char kPrefsUrlSwitchCount[];
 extern const char kPrefsWallClockScatteringWaitPeriod[];
diff --git a/metrics_reporter_android.cc b/metrics_reporter_android.cc
index a5877cb..9165f0d 100644
--- a/metrics_reporter_android.cc
+++ b/metrics_reporter_android.cc
@@ -41,7 +41,7 @@
 constexpr char kMetricsUpdateEngineAttemptResult[] =
     "ota_update_engine_attempt_result";
 constexpr char kMetricsUpdateEngineAttemptDurationInMinutes[] =
-    "ota_update_engine_attempt_duration_boottime_in_minutes";
+    "ota_update_engine_attempt_fixed_duration_boottime_in_minutes";
 constexpr char kMetricsUpdateEngineAttemptDurationUptimeInMinutes[] =
     "ota_update_engine_attempt_duration_monotonic_in_minutes";
 constexpr char kMetricsUpdateEngineAttemptErrorCode[] =
@@ -51,12 +51,12 @@
 constexpr char kMetricsUpdateEngineAttemptPayloadType[] =
     "ota_update_engine_attempt_payload_type";
 constexpr char kMetricsUpdateEngineAttemptCurrentBytesDownloadedMiB[] =
-    "ota_update_engine_attempt_current_bytes_downloaded_mib";
+    "ota_update_engine_attempt_fixed_current_bytes_downloaded_mib";
 
 constexpr char kMetricsUpdateEngineSuccessfulUpdateAttemptCount[] =
     "ota_update_engine_successful_update_attempt_count";
 constexpr char kMetricsUpdateEngineSuccessfulUpdateTotalDurationInMinutes[] =
-    "ota_update_engine_successful_update_total_duration_in_minutes";
+    "ota_update_engine_successful_update_fixed_total_duration_in_minutes";
 constexpr char kMetricsUpdateEngineSuccessfulUpdatePayloadSizeMiB[] =
     "ota_update_engine_successful_update_payload_size_mib";
 constexpr char kMetricsUpdateEngineSuccessfulUpdatePayloadType[] =
@@ -109,7 +109,7 @@
     metrics::DownloadErrorCode /* payload_download_error_code */,
     metrics::ConnectionType /* connection_type */) {
   LogHistogram(metrics::kMetricsUpdateEngineAttemptCurrentBytesDownloadedMiB,
-               payload_bytes_downloaded);
+               payload_bytes_downloaded / kNumBytesInOneMiB);
 }
 
 void MetricsReporterAndroid::ReportSuccessfulUpdateMetrics(
diff --git a/metrics_utils.cc b/metrics_utils.cc
index d80d394..e7b2347 100644
--- a/metrics_utils.cc
+++ b/metrics_utils.cc
@@ -366,10 +366,19 @@
   CHECK(prefs);
   prefs->SetInt64(kPrefsUpdateTimestampStart,
                   update_start_time.ToInternalValue());
-  LOG(INFO) << "Update Timestamp Start = "
+  LOG(INFO) << "Update Monotonic Timestamp Start = "
             << utils::ToString(update_start_time);
 }
 
+void SetUpdateBootTimestampStart(const base::Time& update_start_boot_time,
+                                 PrefsInterface* prefs) {
+  CHECK(prefs);
+  prefs->SetInt64(kPrefsUpdateBootTimestampStart,
+                  update_start_boot_time.ToInternalValue());
+  LOG(INFO) << "Update Boot Timestamp Start = "
+            << utils::ToString(update_start_boot_time);
+}
+
 bool LoadAndReportTimeToReboot(MetricsReporterInterface* metrics_reporter,
                                PrefsInterface* prefs,
                                ClockInterface* clock) {
diff --git a/metrics_utils.h b/metrics_utils.h
index d08cc4a..8f1aad1 100644
--- a/metrics_utils.h
+++ b/metrics_utils.h
@@ -87,10 +87,16 @@
 // Persists the finished time of an update to the |kPrefsSystemUpdatedMarker|.
 void SetSystemUpdatedMarker(ClockInterface* clock, PrefsInterface* prefs);
 
-// Persists the start time of an update to |kPrefsUpdateTimestampStart|.
+// Persists the start monotonic time of an update to
+// |kPrefsUpdateTimestampStart|.
 void SetUpdateTimestampStart(const base::Time& update_start_time,
                              PrefsInterface* prefs);
 
+// Persists the start boot time of an update to
+// |kPrefsUpdateBootTimestampStart|.
+void SetUpdateBootTimestampStart(const base::Time& update_start_boot_time,
+                                 PrefsInterface* prefs);
+
 // Called at program startup if the device booted into a new update.
 // The |time_to_reboot| parameter contains the (monotonic-clock) duration
 // from when the update successfully completed (the value in
diff --git a/update_attempter_android.cc b/update_attempter_android.cc
index 9443869..4d21de6 100644
--- a/update_attempter_android.cc
+++ b/update_attempter_android.cc
@@ -669,10 +669,12 @@
 
   metrics::AttemptResult attempt_result =
       metrics_utils::GetAttemptResult(error_code);
-  Time attempt_start_time = Time::FromInternalValue(
+  Time boot_time_start = Time::FromInternalValue(
+      metrics_utils::GetPersistedValue(kPrefsUpdateBootTimestampStart, prefs_));
+  Time monotonic_time_start = Time::FromInternalValue(
       metrics_utils::GetPersistedValue(kPrefsUpdateTimestampStart, prefs_));
-  TimeDelta duration = clock_->GetBootTime() - attempt_start_time;
-  TimeDelta duration_uptime = clock_->GetMonotonicTime() - attempt_start_time;
+  TimeDelta duration = clock_->GetBootTime() - boot_time_start;
+  TimeDelta duration_uptime = clock_->GetMonotonicTime() - monotonic_time_start;
 
   metrics_reporter_->ReportUpdateAttemptMetrics(
       nullptr,  // system_state
@@ -791,8 +793,8 @@
         metrics_utils::GetPersistedValue(kPrefsPayloadAttemptNumber, prefs_);
     metrics_utils::SetPayloadAttemptNumber(attempt_number + 1, prefs_);
   }
-  Time update_start_time = clock_->GetMonotonicTime();
-  metrics_utils::SetUpdateTimestampStart(update_start_time, prefs_);
+  metrics_utils::SetUpdateTimestampStart(clock_->GetMonotonicTime(), prefs_);
+  metrics_utils::SetUpdateBootTimestampStart(clock_->GetBootTime(), prefs_);
 }
 
 void UpdateAttempterAndroid::ClearMetricsPrefs() {
@@ -802,6 +804,7 @@
   prefs_->Delete(kPrefsPayloadAttemptNumber);
   prefs_->Delete(kPrefsSystemUpdatedMarker);
   prefs_->Delete(kPrefsUpdateTimestampStart);
+  prefs_->Delete(kPrefsUpdateBootTimestampStart);
 }
 
 }  // namespace chromeos_update_engine
diff --git a/update_attempter_android.h b/update_attempter_android.h
index 3faeac9..641374a 100644
--- a/update_attempter_android.h
+++ b/update_attempter_android.h
@@ -130,7 +130,10 @@
   // payload_id.
   // |KprefsNumReboots|: number of reboots when applying the current update.
   // |kPrefsSystemUpdatedMarker|: end timestamp of the last successful update.
-  // |kPrefsUpdateTimestampStart|: start timestamp of the current update.
+  // |kPrefsUpdateTimestampStart|: start timestamp in monotonic time of the
+  // current update.
+  // |kPrefsUpdateBootTimestampStart|: start timestamp in boot time of
+  // the current update.
   // |kPrefsCurrentBytesDownloaded|: number of bytes downloaded for the current
   // payload_id.
   // |kPrefsTotalBytesDownloaded|: number of bytes downloaded in total since
@@ -151,13 +154,14 @@
   void UpdatePrefsAndReportUpdateMetricsOnReboot();
 
   // Prefs to update:
-  //   |kPrefsPayloadAttemptNumber|, |kPrefsUpdateTimestampStart|
+  //   |kPrefsPayloadAttemptNumber|, |kPrefsUpdateTimestampStart|,
+  //   |kPrefsUpdateBootTimestampStart|
   void UpdatePrefsOnUpdateStart(bool is_resume);
 
   // Prefs to delete:
   //   |kPrefsNumReboots|, |kPrefsPayloadAttemptNumber|,
   //   |kPrefsSystemUpdatedMarker|, |kPrefsUpdateTimestampStart|,
-  //   |kPrefsCurrentBytesDownloaded|
+  //   |kPrefsUpdateBootTimestampStart|, |kPrefsCurrentBytesDownloaded|
   void ClearMetricsPrefs();
 
   DaemonStateInterface* daemon_state_;
diff --git a/update_attempter_android_unittest.cc b/update_attempter_android_unittest.cc
index 6b53a21..2593d44 100644
--- a/update_attempter_android_unittest.cc
+++ b/update_attempter_android_unittest.cc
@@ -120,13 +120,14 @@
   prefs_.SetInt64(kPrefsNumReboots, 3);
   prefs_.SetInt64(kPrefsPayloadAttemptNumber, 2);
   prefs_.SetString(kPrefsPreviousVersion, "56789");
+  prefs_.SetInt64(kPrefsUpdateBootTimestampStart, 10000);
   prefs_.SetInt64(kPrefsUpdateTimestampStart, 12345);
 
   Time boot_time = Time::FromInternalValue(22345);
   Time up_time = Time::FromInternalValue(21345);
   clock_->SetBootTime(boot_time);
   clock_->SetMonotonicTime(up_time);
-  TimeDelta duration = boot_time - Time::FromInternalValue(12345);
+  TimeDelta duration = boot_time - Time::FromInternalValue(10000);
   TimeDelta duration_uptime = up_time - Time::FromInternalValue(12345);
   EXPECT_CALL(
       *metrics_reporter_,