diff --git a/demo/index.html b/demo/index.html
index ff097c3..55211d5 100644
--- a/demo/index.html
+++ b/demo/index.html
@@ -6,12 +6,12 @@
   <meta name="viewport" content="width=device-width, initial-scale=1.0">
   <title>&lt;shacl-form&gt; demo</title>
   <link rel="stylesheet" href="./style.css">
-  <!-- "@ulb-darmstadt/shacl-form": "https://cdn.jsdelivr.net/npm/@ulb-darmstadt/shacl-form@1.4.4/dist/" -->
+  <!-- "@ulb-darmstadt/shacl-form": "https://cdn.jsdelivr.net/npm/@ulb-darmstadt/shacl-form@1.4.6/dist/" -->
   <!-- "@ulb-darmstadt/shacl-form": "./" -->
   <script type="importmap">
     {
       "imports": {
-        "@ulb-darmstadt/shacl-form/": "https://cdn.jsdelivr.net/npm/@ulb-darmstadt/shacl-form@1.4.5/dist/"
+        "@ulb-darmstadt/shacl-form/": "https://cdn.jsdelivr.net/npm/@ulb-darmstadt/shacl-form@1.4.6/dist/"
       }
     }
   </script>
diff --git a/src/serialize.ts b/src/serialize.ts
index 77dd818..7ccc59d 100644
--- a/src/serialize.ts
+++ b/src/serialize.ts
@@ -61,6 +61,10 @@ export function toRDF(editor: Editor): Literal | NamedNode | undefined {
             else if (editor['type'] === 'file' && editor['binaryData']) {
                 value = editor['binaryData']
             }
+            else if (editor['type'] === 'datetime-local') {
+                // if seconds in value are 0, the input field omits them which is then not a valid xsd:dateTime
+                value = new Date(value).toISOString().slice(0, 19)
+            }
             return DataFactory.literal(value, languageOrDatatype)
         }
     } else if (editor['type'] === 'checkbox' || editor.getAttribute('type') === 'checkbox') {