diff --git a/frontend/src/index.js b/frontend/src/index.js
index 4a24e54c2..55185ad1b 100644
--- a/frontend/src/index.js
+++ b/frontend/src/index.js
@@ -16,7 +16,7 @@ async function graphHistory(history, path) {
 
   let dateStr = function(timestamp){
     let date = new Date(timestamp);
-    return date.getDate() + '/' + date.getMonth() + '/' + date.getFullYear();
+    return `${date.getDate()}/${date.getMonth() + 1}/${date.getFullYear()}`;
   }
 
   var data = {