diff --git a/scripts/ssh/ssh-exec.php b/scripts/ssh/ssh-exec.php
--- a/scripts/ssh/ssh-exec.php
+++ b/scripts/ssh/ssh-exec.php
@@ -307,7 +307,7 @@
 $ssh_log->setData(
   array(
     'c' => $err,
-    'T' => (int)(1000000 * (microtime(true) - $ssh_start_time)),
+    'T' => phutil_microseconds_since($ssh_start_time),
   ));
 
 exit($err);
diff --git a/src/applications/conduit/controller/PhabricatorConduitAPIController.php b/src/applications/conduit/controller/PhabricatorConduitAPIController.php
--- a/src/applications/conduit/controller/PhabricatorConduitAPIController.php
+++ b/src/applications/conduit/controller/PhabricatorConduitAPIController.php
@@ -109,15 +109,13 @@
       $error_info = $ex->getMessage();
     }
 
-    $time_end = microtime(true);
-
     $log
       ->setCallerPHID(
         isset($conduit_user)
           ? $conduit_user->getPHID()
           : null)
       ->setError((string)$error_code)
-      ->setDuration(1000000 * ($time_end - $time_start));
+      ->setDuration(phutil_microseconds_since($time_start));
 
     if (!PhabricatorEnv::isReadOnly()) {
       $unguarded = AphrontWriteGuard::beginScopedUnguardedWrites();
diff --git a/src/applications/conduit/ssh/ConduitSSHWorkflow.php b/src/applications/conduit/ssh/ConduitSSHWorkflow.php
--- a/src/applications/conduit/ssh/ConduitSSHWorkflow.php
+++ b/src/applications/conduit/ssh/ConduitSSHWorkflow.php
@@ -73,15 +73,13 @@
     // if the response is large and the receiver is slow to read it.
     $this->getIOChannel()->flush();
 
-    $time_end = microtime(true);
-
     $connection_id = idx($metadata, 'connectionID');
     $log = id(new PhabricatorConduitMethodCallLog())
       ->setCallerPHID($this->getSSHUser()->getPHID())
       ->setConnectionID($connection_id)
       ->setMethod($method)
       ->setError((string)$error_code)
-      ->setDuration(1000000 * ($time_end - $time_start))
+      ->setDuration(phutil_microseconds_since($time_start))
       ->save();
   }
 }
diff --git a/src/applications/diffusion/engine/DiffusionCommitHookEngine.php b/src/applications/diffusion/engine/DiffusionCommitHookEngine.php
--- a/src/applications/diffusion/engine/DiffusionCommitHookEngine.php
+++ b/src/applications/diffusion/engine/DiffusionCommitHookEngine.php
@@ -1113,14 +1113,13 @@
     $viewer = $this->getViewer();
 
     $hook_start = $this->getStartTime();
-    $hook_end = microtime(true);
 
     $event = PhabricatorRepositoryPushEvent::initializeNewEvent($viewer)
       ->setRepositoryPHID($this->getRepository()->getPHID())
       ->setRemoteAddress($this->getRemoteAddress())
       ->setRemoteProtocol($this->getRemoteProtocol())
       ->setEpoch(PhabricatorTime::getNow())
-      ->setHookWait((int)(1000000 * ($hook_end - $hook_start)));
+      ->setHookWait(phutil_microseconds_since($hook_start));
 
     $identifier = $this->getRequestIdentifier();
     if (strlen($identifier)) {
diff --git a/src/applications/diffusion/protocol/DiffusionRepositoryClusterEngine.php b/src/applications/diffusion/protocol/DiffusionRepositoryClusterEngine.php
--- a/src/applications/diffusion/protocol/DiffusionRepositoryClusterEngine.php
+++ b/src/applications/diffusion/protocol/DiffusionRepositoryClusterEngine.php
@@ -772,8 +772,7 @@
     try {
       $future->resolvex();
     } catch (Exception $ex) {
-      $sync_end = microtime(true);
-      $log->setSyncWait((int)(1000000 * ($sync_end - $sync_start)));
+      $log->setSyncWait(phutil_microseconds_since($sync_start));
 
       if ($ex instanceof CommandException) {
         if ($future->getWasKilledByTimeout()) {
@@ -806,10 +805,8 @@
       throw $ex;
     }
 
-    $sync_end = microtime(true);
-
     $log
-      ->setSyncWait((int)(1000000 * ($sync_end - $sync_start)))
+      ->setSyncWait(phutil_microseconds_since($sync_start))
       ->setResultCode(0)
       ->setResultType(PhabricatorRepositorySyncEvent::RESULT_SYNC)
       ->save();
diff --git a/src/infrastructure/daemon/workers/storage/PhabricatorWorkerActiveTask.php b/src/infrastructure/daemon/workers/storage/PhabricatorWorkerActiveTask.php
--- a/src/infrastructure/daemon/workers/storage/PhabricatorWorkerActiveTask.php
+++ b/src/infrastructure/daemon/workers/storage/PhabricatorWorkerActiveTask.php
@@ -169,8 +169,7 @@
 
       $t_start = microtime(true);
         $worker->executeTask();
-      $t_end = microtime(true);
-      $duration = (int)(1000000 * ($t_end - $t_start));
+      $duration = phutil_microseconds_since($t_start);
 
       $result = $this->archiveTask(
         PhabricatorWorkerArchiveTask::RESULT_SUCCESS,
diff --git a/support/startup/PhabricatorStartup.php b/support/startup/PhabricatorStartup.php
--- a/support/startup/PhabricatorStartup.php
+++ b/support/startup/PhabricatorStartup.php
@@ -64,6 +64,8 @@
    * @task info
    */
   public static function getMicrosecondsSinceStart() {
+    // This is the same as "phutil_microseconds_since()", but we may not have
+    // loaded libphutil yet.
     return (int)(1000000 * (microtime(true) - self::getStartTime()));
   }