diff --git a/src/Serval/src/Serval.ApiServer/nswag.json b/src/Serval/src/Serval.ApiServer/nswag.json
index e7f6c25b..931d141e 100644
--- a/src/Serval/src/Serval.ApiServer/nswag.json
+++ b/src/Serval/src/Serval.ApiServer/nswag.json
@@ -46,7 +46,7 @@
       "generateContractsOutput": false,
       "contractsNamespace": null,
       "contractsOutputFilePath": null,
-      "parameterDateTimeFormat": "s",
+      "parameterDateTimeFormat": "u",
       "parameterDateFormat": "yyyy-MM-dd",
       "generateUpdateJsonSerializerSettingsMethod": true,
       "useRequestAndResponseSerializationSettings": false,
diff --git a/src/Serval/src/Serval.Client/Client.g.cs b/src/Serval/src/Serval.Client/Client.g.cs
index 4f41e11b..1ccb305f 100644
--- a/src/Serval/src/Serval.Client/Client.g.cs
+++ b/src/Serval/src/Serval.Client/Client.g.cs
@@ -2278,7 +2278,7 @@ public string BaseUrl
                     urlBuilder_.Append('?');
                     if (createdAfter != null)
                     {
-                        urlBuilder_.Append(System.Uri.EscapeDataString("created-after")).Append('=').Append(System.Uri.EscapeDataString(createdAfter.Value.ToString("s", System.Globalization.CultureInfo.InvariantCulture))).Append('&');
+                        urlBuilder_.Append(System.Uri.EscapeDataString("created-after")).Append('=').Append(System.Uri.EscapeDataString(createdAfter.Value.ToString("u", System.Globalization.CultureInfo.InvariantCulture))).Append('&');
                     }
                     urlBuilder_.Length--;
 
@@ -2380,7 +2380,7 @@ public string BaseUrl
                     urlBuilder_.Append('?');
                     if (finishedAfter != null)
                     {
-                        urlBuilder_.Append(System.Uri.EscapeDataString("finished-after")).Append('=').Append(System.Uri.EscapeDataString(finishedAfter.Value.ToString("s", System.Globalization.CultureInfo.InvariantCulture))).Append('&');
+                        urlBuilder_.Append(System.Uri.EscapeDataString("finished-after")).Append('=').Append(System.Uri.EscapeDataString(finishedAfter.Value.ToString("u", System.Globalization.CultureInfo.InvariantCulture))).Append('&');
                     }
                     urlBuilder_.Length--;