From 88548e9738fc3f9334da934a96a3d1af1acb9957 Mon Sep 17 00:00:00 2001
From: Ferdinand Prantl <prantlf@gmail.com>
Date: Wed, 26 Sep 2018 09:49:07 +0200
Subject: [PATCH] Do not clone the Date instance needlessly in toISOString

---
 src/index.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/index.js b/src/index.js
index 58bb30423..bc036c48f 100644
--- a/src/index.js
+++ b/src/index.js
@@ -422,7 +422,7 @@ class Dayjs {
     // ie 8 return
     // new Dayjs(this.valueOf() + this.$d.getTimezoneOffset() * 60000)
     // .format('YYYY-MM-DDTHH:mm:ss.SSS[Z]')
-    return this.toDate().toISOString()
+    return this.$d.toISOString()
   }
 
   toObject() {