diff --git a/src/applications/config/check/PhabricatorSetupCheckTimezone.php b/src/applications/config/check/PhabricatorSetupCheckTimezone.php
index 834afb14b1..ebff55f6f6 100644
--- a/src/applications/config/check/PhabricatorSetupCheckTimezone.php
+++ b/src/applications/config/check/PhabricatorSetupCheckTimezone.php
@@ -3,6 +3,26 @@
 final class PhabricatorSetupCheckTimezone extends PhabricatorSetupCheck {
 
   protected function executeChecks() {
+    $php_value = ini_get('date.timezone');
+    if ($php_value) {
+      $old = date_default_timezone_get();
+      $ok = @date_default_timezone_set($php_value);
+      date_default_timezone_set($old);
+
+      if (!$ok) {
+        $message = pht(
+          'Your PHP configuration configuration selects an invalid timezone. '.
+          'Select a valid timezone.');
+
+        $this
+          ->newIssue('php.date.timezone')
+          ->setShortName(pht('PHP Timezone'))
+          ->setName(pht('PHP Timezone Invalid'))
+          ->setMessage($message)
+          ->addPHPConfig('date.timezone');
+      }
+    }
+
     $timezone = nonempty(
       PhabricatorEnv::getEnvConfig('phabricator.timezone'),
       ini_get('date.timezone'));
diff --git a/src/infrastructure/PhabricatorSetup.php b/src/infrastructure/PhabricatorSetup.php
index 7e7edfef15..8645b9c729 100644
--- a/src/infrastructure/PhabricatorSetup.php
+++ b/src/infrastructure/PhabricatorSetup.php
@@ -358,22 +358,6 @@ final class PhabricatorSetup {
       }
     }
 
-    $timezone = nonempty(
-      PhabricatorEnv::getEnvConfig('phabricator.timezone'),
-      ini_get('date.timezone'));
-    if (!$timezone) {
-      self::writeFailure();
-      self::write(
-        "Setup failure! Your configuration fails to specify a server ".
-        "timezone. Either set 'date.timezone' in your php.ini or ".
-        "'phabricator.timezone' in your Phabricator configuration. See the ".
-        "PHP documentation for a list of supported timezones:\n\n".
-        "http://www.php.net/manual/en/timezones.php\n");
-      return;
-    } else {
-      self::write(" okay  Timezone '{$timezone}' configured.\n");
-    }
-
     self::write("[OKAY] Basic configuration OKAY\n");
 
 
@@ -587,24 +571,6 @@ final class PhabricatorSetup {
       self::write(" skip  Not configured for local disk storage.\n");
     }
 
-    $selector = PhabricatorEnv::getEnvConfig('storage.engine-selector');
-
-    try {
-      $storage_selector_exists = class_exists($selector);
-    } catch (Exception $ex) {
-      $storage_selector_exists = false;
-    }
-
-    if ($storage_selector_exists) {
-      self::write(" okay  Using '{$selector}' as a storage engine selector.\n");
-    } else {
-      self::writeFailure();
-      self::write(
-        "Setup failure! You have configured '{$selector}' as a storage engine ".
-        "selector but it does not exist or could not be loaded.\n");
-      return;
-    }
-
     self::write("[OKAY] Database and storage configuration OKAY\n");
 
     self::writeHeader('SUCCESS!');
diff --git a/src/infrastructure/env/PhabricatorEnv.php b/src/infrastructure/env/PhabricatorEnv.php
index 79c6b40c49..627b70bcbc 100644
--- a/src/infrastructure/env/PhabricatorEnv.php
+++ b/src/infrastructure/env/PhabricatorEnv.php
@@ -107,9 +107,15 @@ final class PhabricatorEnv {
 
     self::buildConfigurationSourceStack();
 
+    // Force a valid timezone. If both PHP and Phabricator configuration are
+    // invalid, use UTC.
     $tz = PhabricatorEnv::getEnvConfig('phabricator.timezone');
     if ($tz) {
-      date_default_timezone_set($tz);
+      @date_default_timezone_set($tz);
+    }
+    $ok = @date_default_timezone_set(date_default_timezone_get());
+    if (!$ok) {
+      date_default_timezone_set('UTC');
     }
 
     // Append any paths to $PATH if we need to.