diff --git a/reference/datetime/datetimeinterface/serialize.xml b/reference/datetime/datetimeinterface/serialize.xml
index 5615dca18157..0a6934b9b630 100644
--- a/reference/datetime/datetimeinterface/serialize.xml
+++ b/reference/datetime/datetimeinterface/serialize.xml
@@ -43,24 +43,51 @@
  <refsect1 role="examples">
   &reftitle.examples;
   <example>
-   <title><function>DateTime::serialize</function> example</title>
+   <title><methodname>DateTime::__serialize</methodname> example</title>
    <programlisting role="php">
 <![CDATA[
 <?php
-$date = new DateTime('2025-03-27');
+
+class CustomDateTimeImmutable extends DateTimeImmutable
+{
+    #[\Override]
+    public function __serialize(): array
+    {
+        return [
+            'date' => $this->format(DateTimeInterface::W3C),
+            'timestamp' => $this->getTimestamp(),
+            'timezone' => $this->getTimeZone()->getName(),
+            'to' => 'Drink a cup of coffee',
+        ];
+    }
+}
+
+$date = new CustomDateTimeImmutable('2025-03-27');
 var_dump(serialize($date));
+
 ?>
 ]]>
    </programlisting>
    &examples.outputs;
    <screen>
 <![CDATA[
-string(114) "O:8:"DateTime":3:{s:4:"date";s:26:"2025-03-27 00:00:00.000000";s:13:"timezone_type";i:3;s:8:"timezone";s:3:"UTC";}"
+string(171) "O:23:"CustomDateTimeImmutable":4:{s:4:"date";s:25:"2025-03-27T00:00:00+00:00";s:9:"timestamp";i:1743033600;s:8:"timezone";s:3:"UTC";s:2:"to";s:21:"Drink a cup of coffee";}"
 ]]>
    </screen>
   </example>
  </refsect1>
 
+ <refsect1 role="notes">
+  &reftitle.notes;
+  <warning>
+   <para>
+    An <classname>Error</classname> is thrown when attempting to unserialize a custom
+    <classname>DateTime</classname> object if the <link linkend="object.serialize">__serialize()</link> is
+    defined but the <link linkend="object.unserialize">__unserialize()</link> is missing.
+   </para>
+  </warning>
+ </refsect1>
+
  <refsect1 role="seealso">
   &reftitle.seealso;
   <simplelist>
diff --git a/reference/datetime/datetimeinterface/unserialize.xml b/reference/datetime/datetimeinterface/unserialize.xml
index f60f36c4bb9e..d33005a44b91 100644
--- a/reference/datetime/datetimeinterface/unserialize.xml
+++ b/reference/datetime/datetimeinterface/unserialize.xml
@@ -44,19 +44,33 @@
  <refsect1 role="returnvalues">
   &reftitle.returnvalues;
   <para>
-   The <classname>DateTime</classname> object.
+   &return.void;
   </para>
  </refsect1>
 
  <refsect1 role="examples">
   &reftitle.examples;
   <example>
-   <title><function>DateTime::unserialize</function> example</title>
+   <title><methodname>DateTime::__unserialize</methodname> example</title>
    <programlisting role="php">
 <![CDATA[
 <?php
-$serializedDate = 'O:8:"DateTime":3:{s:4:"date";s:26:"2025-03-27 00:00:00.000000";s:13:"timezone_type";i:3;s:8:"timezone";s:3:"UTC";}';
-var_dump(unserialize($serializedDate));
+
+class CustomDateTimeImmutable extends DateTimeImmutable
+{
+    #[\Override]
+    public function __unserialize(array $data): void
+    {
+        echo "Time to `{$data['to']}`:\n\n";
+
+        $this->__construct($data['date'], new DateTimeZone($data['timezone']));
+    }
+}
+
+$serializedData = 'O:23:"CustomDateTimeImmutable":4:{s:4:"date";s:25:"2025-03-27T00:00:00+00:00";s:9:"timestamp";i:1743033600;s:8:"timezone";s:3:"UTC";s:2:"to";s:21:"Drink a cup of coffee";}';
+
+var_dump(unserialize($serializedData));
+
 ?>
 ]]>
    </programlisting>
@@ -76,6 +90,17 @@ object(DateTime)#1 (3) {
   </example>
  </refsect1>
 
+ <refsect1 role="notes">
+  &reftitle.notes;
+  <warning>
+   <para>
+    An <classname>Error</classname> is thrown when attempting to unserialize a custom
+    <classname>DateTime</classname> object if the <link linkend="object.serialize">__serialize()</link> is
+    defined but the <link linkend="object.unserialize">__unserialize()</link> is missing.
+   </para>
+  </warning>
+ </refsect1>
+
  <refsect1 role="seealso">
   &reftitle.seealso;
   <simplelist>