diff --git a/CHANGELOG.md b/CHANGELOG.md
index 97d9dcf7..53715b8d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,9 @@
 # CHANGELOG
 
+## v6.9.1 (2023-11-20)
+
+- Fixes a bug that globally reset the timezone to UTC instead of setting the timezone per-request (closes #310)
+
 ## v6.9.0 (2023-10-11)
 
 - Deprecates API key-related functions in the `user` service and introduces the replacement functions in the `api_keys` service
diff --git a/composer.json b/composer.json
index 95b6e97a..621ca9ff 100644
--- a/composer.json
+++ b/composer.json
@@ -1,7 +1,7 @@
 {
   "name": "easypost/easypost-php",
   "description": "EasyPost Shipping API Client Library for PHP",
-  "version": "6.9.0",
+  "version": "6.9.1",
   "keywords": [
     "shipping",
     "api",
diff --git a/lib/EasyPost/Constant/Constants.php b/lib/EasyPost/Constant/Constants.php
index 45c5b7d8..d79d18c4 100644
--- a/lib/EasyPost/Constant/Constants.php
+++ b/lib/EasyPost/Constant/Constants.php
@@ -11,7 +11,7 @@ abstract class Constants
     const BETA_API_VERSION = 'beta';
 
     // Library constants
-    const LIBRARY_VERSION = '6.9.0';
+    const LIBRARY_VERSION = '6.9.1';
     const SUPPORT_EMAIL = 'support@easypost.com';
 
     // Validation
diff --git a/lib/EasyPost/Http/Requestor.php b/lib/EasyPost/Http/Requestor.php
index b70db9ac..ef2dae03 100644
--- a/lib/EasyPost/Http/Requestor.php
+++ b/lib/EasyPost/Http/Requestor.php
@@ -183,9 +183,7 @@ private static function requestRaw($client, $method, $url, $params, $beta = fals
         ];
 
         $requestUuid = uniqid();
-        $originalTimezone = date_default_timezone_get();
-        date_default_timezone_set('UTC');
-        $requestTimestamp = microtime(true);
+        $requestTimestamp = (float) (new DateTime('now', new DateTimeZone('UTC')))->format('U.u');
         ($client->requestEvent)([
             'method' => $method,
             'path' => $absoluteUrl,
@@ -226,7 +224,7 @@ private static function requestRaw($client, $method, $url, $params, $beta = fals
             $responseHeaders = $response->getHeaders();
         }
 
-        $responseTimestamp = microtime(true);
+        $responseTimestamp = (float) (new DateTime('now', new DateTimeZone('UTC')))->format('U.u');
         ($client->responseEvent)([
             'http_status' => $httpStatus,
             'method' => $method,
@@ -238,9 +236,6 @@ private static function requestRaw($client, $method, $url, $params, $beta = fals
             'request_uuid' => $requestUuid,
         ]);
 
-        // Reset the timezone after we've done our UTC calculations so we don't affect user code
-        date_default_timezone_set($originalTimezone);
-
         return [$responseBody, $httpStatus];
     }