Добавил форматер даты

src/Transformer/DateTimeFormat.php

@@ -0,0 +1,14 @@
+<?php
+
+namespace Rinsvent\DTO2Data\Transformer;
+
+#[\Attribute(\Attribute::TARGET_ALL|\Attribute::IS_REPEATABLE)]
+class DateTimeFormat extends Meta
+{
+    public function __construct(
+        public array $tags = ['default'],
+        public string $format = \DateTimeInterface::ATOM
+    ) {
+        parent::__construct(...func_get_args());
+    }
+}

src/Transformer/DateTimeFormatTransformer.php

@@ -0,0 +1,18 @@
+<?php
+
+namespace Rinsvent\DTO2Data\Transformer;
+
+class DateTimeFormatTransformer implements TransformerInterface
+{
+    /**
+     * @param \DateTimeImmutable|\DateTime|null $data
+     * @param DateTimeFormat $meta
+     */
+    public function transform(&$data, Meta $meta): void
+    {
+        if ($data === null) {
+            return;
+        }
+        $data = $data->format($meta->format);
+    }
+}