Align sysstat timezone with system

app/Filament/Admin/Widgets/ServerChartsWidget.php

@@ -34,7 +34,8 @@ class ServerChartsWidget extends Widget
         $this->refreshKey++;
         $data = $this->getData();
         $config = $this->rangeConfig($this->range);
-        $label = now()->format($config['label_format']);
+        $sysstat = new SysstatMetrics;
+        $label = now($sysstat->timezoneName())->format($config['label_format']);
 
         $this->dispatch('server-charts-updated', [
             'cpu' => $data['cpu']['usage'] ?? 0,

app/Services/SysstatMetrics.php

@@ -5,6 +5,7 @@ declare(strict_types=1);
 namespace App\Services;
 
 use Carbon\CarbonImmutable;
+use DateTimeZone;
 use Symfony\Component\Process\Process;
 
 class SysstatMetrics
@@ -18,7 +19,8 @@ class SysstatMetrics
             return [];
         }
 
-        $end = CarbonImmutable::now()->second(0);
+        $timezone = $this->systemTimezone();
+        $end = CarbonImmutable::now($timezone)->second(0);
         if ($intervalSeconds >= 3600) {
             $end = $end->minute(0);
         }
@@ -40,7 +42,8 @@ class SysstatMetrics
      */
     public function latest(): ?array
     {
-        $end = CarbonImmutable::now();
+        $timezone = $this->systemTimezone();
+        $end = CarbonImmutable::now($timezone);
         $start = $end->subMinutes(15);
         $samples = $this->readSamples($start, $end);
 
@@ -63,6 +66,11 @@ class SysstatMetrics
         ];
     }
 
+    public function timezoneName(): string
+    {
+        return $this->systemTimezone()->getName();
+    }
+
     /**
      * @return array<int, array{timestamp: int, load1: float, load5: float, load15: float, iowait: float, memory: float, swap: float}>
      */
@@ -227,7 +235,7 @@ class SysstatMetrics
             return null;
         }
 
-        $value = CarbonImmutable::createFromFormat('Y-m-d H:i:s', $date.' '.$time, config('app.timezone'));
+        $value = CarbonImmutable::createFromFormat('Y-m-d H:i:s', $date.' '.$time, $this->systemTimezone());
         if ($value === false) {
             return null;
         }
@@ -235,6 +243,37 @@ class SysstatMetrics
         return $value;
     }
 
+    private function systemTimezone(): DateTimeZone
+    {
+        static $timezone = null;
+
+        if ($timezone instanceof DateTimeZone) {
+            return $timezone;
+        }
+
+        $name = getenv('TZ') ?: null;
+        if (! $name && is_file('/etc/timezone')) {
+            $name = trim((string) file_get_contents('/etc/timezone'));
+        }
+        if (! $name && is_link('/etc/localtime')) {
+            $target = readlink('/etc/localtime');
+            if (is_string($target) && str_contains($target, '/zoneinfo/')) {
+                $name = substr($target, strpos($target, '/zoneinfo/') + 10);
+            }
+        }
+        if (! $name) {
+            $name = config('app.timezone') ?: date_default_timezone_get();
+        }
+
+        try {
+            $timezone = new DateTimeZone($name);
+        } catch (\Exception $e) {
+            $timezone = new DateTimeZone('UTC');
+        }
+
+        return $timezone;
+    }
+
     /**
      * @param  array<string, mixed>  $source
      */