[6.x] UTC form submission dates

src/Forms/Submission.php

@@ -58,7 +58,9 @@ public function id($id = null)
     {
         return $this->fluentlyGetOrSet('id')
             ->getter(function ($id) {
-                return $this->id = $id ?: str_replace(',', '.', microtime(true));
+                $micro = Carbon::now()->timestamp + Carbon::now()->micro / 1000000;
+
+                return $this->id = $id ?: str_replace(',', '.', $micro);
             })
             ->args(func_get_args());
     }
@@ -101,7 +103,7 @@ public function columns()
      */
     public function date()
     {
-        return Carbon::createFromTimestamp($this->id(), config('app.timezone'));
+        return Carbon::createFromTimestamp($this->id());
     }
 
     /**
@@ -111,7 +113,7 @@ public function date()
      */
     public function formattedDate()
     {
-        return $this->date()->format(
+        return $this->date()->tz(config('app.timezone'))->format(
             $this->form()->dateFormat()
         );
     }

src/Http/Resources/CP/Submissions/ListedSubmission.php

@@ -32,7 +32,7 @@ public function toArray($request)
         return [
             'id' => $this->resource->id(),
             $this->merge($this->values([
-                'datestamp' => $this->resource->date()->format($form->dateFormat()),
+                'datestamp' => $this->resource->date()->tz(config('app.timezone'))->format($form->dateFormat()),
             ])),
             'url' => cp_route('forms.submissions.show', [$form->handle(), $this->resource->id()]),
             'deleteable' => User::current()->can('delete', $this->resource),

tests/Forms/SubmissionTest.php

@@ -2,8 +2,10 @@
 
 namespace Tests\Forms;
 
+use Carbon\Carbon;
 use Illuminate\Support\Collection;
 use Illuminate\Support\Facades\Event;
+use PHPUnit\Framework\Attributes\DataProvider;
 use PHPUnit\Framework\Attributes\Test;
 use Statamic\Events\SubmissionCreated;
 use Statamic\Events\SubmissionCreating;
@@ -49,6 +51,28 @@ public function generated_ids_dont_have_commas()
         setlocale(LC_TIME, $originalLocale);
     }
 
+    #[Test]
+    #[DataProvider('utcProvider')]
+    public function the_date_is_utc($tz, $expectedFormatted)
+    {
+        config(['app.timezone' => $tz]);
+
+        Carbon::setTestNow(Carbon::parse('2025-03-12 02:13:25', 'UTC'));
+
+        $submission = Form::make('test')->makeSubmission();
+
+        $this->assertEquals('2025-03-12T02:13:25+00:00', $submission->date()->toIso8601String());
+        $this->assertEquals($expectedFormatted, $submission->formattedDate());
+    }
+
+    public static function utcProvider()
+    {
+        return [
+            'utc' => ['UTC', 'March 12th, 2025 02:13'],
+            'not utc' => ['America/New_York', 'March 11th, 2025 22:13'],
+        ];
+    }
+
     #[Test]
     public function it_sets_and_gets_data()
     {