Bug fixed in for statement
diff --git a/js/build_page.js b/js/build_page.js
index 81b76ed..13a8a3a 100644
--- a/js/build_page.js
+++ b/js/build_page.js
@@ -113,7 +113,7 @@
     var duplicateSubjectBoolNext, duplicateSubjectBoolPrev;

     var duplicateSubjectCounter = 0;

     

-    for (var [i, classe] of classes) {        

+    for (var [i, classe] of classes.entries()) {        

         var hora_inici = formatDate(new Date(parseInt(classe.begins)*1000));

         var hora_final = formatDate(new Date(parseInt(classe.ends)*1000));

         var classeDiv = document.createElement('div');