diff --git a/app/Models/Device.php b/app/Models/Device.php
index 21f5c6c..d786d2e 100644
--- a/app/Models/Device.php
+++ b/app/Models/Device.php
@@ -218,12 +218,22 @@ class Device extends Model
         $to = $this->sleep_mode_to;
 
         // Handle overnight ranges (e.g. 22:00 to 06:00)
-        if ($this->sleep_mode_from < $to) {
+        if ($from < $to) {
+            // Normal range, same day
             return $now->between($from, $to) ? (int) $now->diffInSeconds($to, false) : null;
+        } else {
+            // Overnight range
+            if ($now->gte($from)) {
+                // After 'from', before midnight
+                return (int) $now->diffInSeconds($to->copy()->addDay(), false);
+            } elseif ($now->lt($to)) {
+                // After midnight, before 'to'
+                return (int) $now->diffInSeconds($to, false);
+            } else {
+                // Not in sleep window
+                return null;
+            }
         }
-
-        return ($now->gte($from) || $now->lt($to)) ? (int) $now->diffInSeconds($to->addDay(), false) : null;
-
     }
 
     public function isPauseActive(): bool
diff --git a/tests/Feature/Devices/DeviceTest.php b/tests/Feature/Devices/DeviceTest.php
index 6848bdd..e03a82a 100644
--- a/tests/Feature/Devices/DeviceTest.php
+++ b/tests/Feature/Devices/DeviceTest.php
@@ -1,6 +1,7 @@
 <?php
 
 use App\Models\Device;
+use Illuminate\Support\Carbon;
 
 uses(Illuminate\Foundation\Testing\RefreshDatabase::class);
 
@@ -74,3 +75,20 @@ test('last log request is properly cast to json', function () {
         ->toHaveKey('status')
         ->toHaveKey('timestamp');
 });
+
+test('getSleepModeEndsInSeconds returns correct value for overnight sleep window', function () {
+    // Set the current time to 12:13
+    Carbon::setTestNow(Carbon::create(2024, 1, 1, 12, 13, 0));
+
+    $device = Device::factory()->create([
+        'sleep_mode_enabled' => true,
+        'sleep_mode_from' => Carbon::create(2024, 1, 1, 22, 0, 0), // 22:00
+        'sleep_mode_to' => Carbon::create(2024, 1, 1, 13, 0, 0),   // 13:00
+    ]);
+
+    $seconds = $device->getSleepModeEndsInSeconds();
+    // 47 minutes = 2820 seconds
+    expect($seconds)->toBe(2820);
+
+    Carbon::setTestNow(); // Clear test time
+});