Support setting timezone on clock tool

Author: chr-hertel

src/agent/src/Toolbox/Tool/Clock.php

@@ -23,15 +23,22 @@
 {
     public function __construct(
         private ClockInterface $clock = new SymfonyClock(),
+        private ?string $timezone = null,
     ) {
     }
 
     public function __invoke(): string
     {
+        $now = $this->clock->now();
+
+        if (null !== $this->timezone) {
+            $now = $now->setTimezone(new \DateTimeZone($this->timezone));
+        }
+
         return \sprintf(
             'Current date is %s (YYYY-MM-DD) and the time is %s (HH:MM:SS).',
-            $this->clock->now()->format('Y-m-d'),
-            $this->clock->now()->format('H:i:s'),
+            $now->format('Y-m-d'),
+            $now->format('H:i:s'),
         );
     }
 }

src/agent/tests/Toolbox/Tool/ClockTest.php

@@ -0,0 +1,39 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\AI\Agent\Tests\Toolbox\Tool;
+
+use PHPUnit\Framework\Attributes\CoversClass;
+use PHPUnit\Framework\TestCase;
+use Symfony\AI\Agent\Toolbox\Tool\Clock;
+use Symfony\Component\Clock\MockClock;
+
+#[CoversClass(Clock::class)]
+class ClockTest extends TestCase
+{
+    public function testInvokeReturnsCurrentDateTime()
+    {
+        $frozen = new MockClock('2024-06-01 12:00:00', new \DateTimeZone('UTC'));
+        $clock = new Clock($frozen);
+        $output = $clock();
+
+        $this->assertSame('Current date is 2024-06-01 (YYYY-MM-DD) and the time is 12:00:00 (HH:MM:SS).', $output);
+    }
+
+    public function testInvokeWithCustomTimezone()
+    {
+        $frozen = new MockClock('2024-06-01 12:00:00', new \DateTimeZone('UTC'));
+        $clock = new Clock($frozen, 'America/New_York');
+        $output = $clock();
+
+        $this->assertSame('Current date is 2024-06-01 (YYYY-MM-DD) and the time is 08:00:00 (HH:MM:SS).', $output);
+    }
+}