diff --git a/src/js/calendar.js b/src/js/calendar.js
index 920bf98..d34a7ce 100644
--- a/src/js/calendar.js
+++ b/src/js/calendar.js
@@ -1,3 +1,21 @@
+/* (license-header)
+ * hores
+ * Copyright (c) 2023 Adrià Vilanova Martínez
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public
+ * License along with this program.
+ * If not, see http://www.gnu.org/licenses/.
+ */
 document.addEventListener("DOMContentLoaded", _ => {
   document.querySelectorAll("select").forEach(el => {
     el.addEventListener("change", _ => {