diff --git a/src/utils.js b/src/utils.js
new file mode 100644
index 0000000..7644e4b
--- /dev/null
+++ b/src/utils.js
@@ -0,0 +1,12 @@
+ 
+const dateString = (date) => {
+  const ye = new Intl.DateTimeFormat('en', { year: 'numeric' }).format(date)
+  const mo = new Intl.DateTimeFormat('en', { month: '2-digit' }).format(date)
+  const da = new Intl.DateTimeFormat('en', { day: '2-digit' }).format(date)
+
+  return `${ye}-${mo}-${da}`
+}
+
+module.exports = {
+  dateString
+}