diff --git a/src/Logs/HorizonLog.php b/src/Logs/HorizonLog.php
index 4e37cf56..080a5ad4 100644
--- a/src/Logs/HorizonLog.php
+++ b/src/Logs/HorizonLog.php
@@ -20,7 +20,7 @@ class HorizonLog extends Log
     protected function fillMatches(array $matches = []): void
     {
         $datetime = $this->parseDateTime($matches['datetime'] ?? null);
-        $timezone = config('log-viewer.timezone', config('app.timezone', 'UTC'));
+        $timezone = config('log-viewer.timezone', config('app.timezone', 'UTC')) ?? 'UTC';
         $this->datetime = $datetime?->setTimezone($timezone);
 
         $this->level = $matches['level'];
diff --git a/src/Logs/HorizonOldLog.php b/src/Logs/HorizonOldLog.php
index 63072338..a714e4f2 100644
--- a/src/Logs/HorizonOldLog.php
+++ b/src/Logs/HorizonOldLog.php
@@ -19,7 +19,7 @@ class HorizonOldLog extends Log
     protected function fillMatches(array $matches = []): void
     {
         $datetime = static::parseDateTime($matches['datetime'] ?? null);
-        $timezone = config('log-viewer.timezone', config('app.timezone', 'UTC'));
+        $timezone = config('log-viewer.timezone', config('app.timezone', 'UTC')) ?? 'UTC';
         $this->datetime = $datetime?->setTimezone($timezone);
 
         $this->level = $matches['level'];
diff --git a/src/Logs/HttpAccessLog.php b/src/Logs/HttpAccessLog.php
index ad5b406b..dc9f8765 100644
--- a/src/Logs/HttpAccessLog.php
+++ b/src/Logs/HttpAccessLog.php
@@ -35,7 +35,7 @@ protected function fillMatches(array $matches = []): void
         ];
 
         $datetime = static::parseDateTime($matches['datetime'] ?? null);
-        $timezone = config('log-viewer.timezone', config('app.timezone', 'UTC'));
+        $timezone = config('log-viewer.timezone', config('app.timezone', 'UTC')) ?? 'UTC';
         $this->datetime = $datetime?->setTimezone($timezone);
 
         $this->level = $matches['status_code'] ?? null;
diff --git a/src/Logs/HttpApacheErrorLog.php b/src/Logs/HttpApacheErrorLog.php
index 7dcb0717..c4932541 100644
--- a/src/Logs/HttpApacheErrorLog.php
+++ b/src/Logs/HttpApacheErrorLog.php
@@ -15,7 +15,7 @@ class HttpApacheErrorLog extends Log
     protected function fillMatches(array $matches = []): void
     {
         $datetime = static::parseDateTime($matches['datetime'] ?? null);
-        $timezone = config('log-viewer.timezone', config('app.timezone', 'UTC'));
+        $timezone = config('log-viewer.timezone', config('app.timezone', 'UTC')) ?? 'UTC';
         $this->datetime = $datetime?->setTimezone($timezone);
 
         $this->level = $matches['level'] ?? null;
diff --git a/src/Logs/HttpNginxErrorLog.php b/src/Logs/HttpNginxErrorLog.php
index 6b43f9bc..4e4e1fc6 100644
--- a/src/Logs/HttpNginxErrorLog.php
+++ b/src/Logs/HttpNginxErrorLog.php
@@ -15,7 +15,7 @@ class HttpNginxErrorLog extends Log
     protected function fillMatches(array $matches = []): void
     {
         $datetime = static::parseDateTime($matches['datetime'] ?? null);
-        $timezone = config('log-viewer.timezone', config('app.timezone', 'UTC'));
+        $timezone = config('log-viewer.timezone', config('app.timezone', 'UTC')) ?? 'UTC';
         $this->datetime = $datetime?->setTimezone($timezone);
 
         $this->level = $matches['level'] ?? null;
diff --git a/src/Logs/Log.php b/src/Logs/Log.php
index 60a1e9b5..203c12e9 100644
--- a/src/Logs/Log.php
+++ b/src/Logs/Log.php
@@ -105,7 +105,7 @@ protected function parseText(array &$matches = []): void
     protected function fillMatches(array $matches = []): void
     {
         $datetime = static::parseDateTime($matches['datetime'] ?? null);
-        $timezone = config('log-viewer.timezone', config('app.timezone', 'UTC'));
+        $timezone = config('log-viewer.timezone', config('app.timezone', 'UTC')) ?? 'UTC';
         $this->datetime = $datetime?->setTimezone($timezone);
 
         $this->level = $matches[static::$regexLevelKey] ?? null;