From b418048bc99cabc24e875e0ed3a602bd68957749 Mon Sep 17 00:00:00 2001
From: Paulus Schoutsen <balloob@gmail.com>
Date: Mon, 22 Oct 2018 21:07:31 +0200
Subject: [PATCH] Fix chart tooltip

---
 src/components/state-history-chart-timeline.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/components/state-history-chart-timeline.js b/src/components/state-history-chart-timeline.js
index 924eba092f..7aae50b7f8 100644
--- a/src/components/state-history-chart-timeline.js
+++ b/src/components/state-history-chart-timeline.js
@@ -150,7 +150,7 @@ class StateHistoryChartTimeline extends LocalizeMixin(PolymerElement) {
       labels.push(entityDisplay);
     });
 
-    const formatTooltipLabel = function(item, data) {
+    const formatTooltipLabel = (item, data) => {
       const values = data.datasets[item.datasetIndex].data[item.index];
 
       const start = formatDateTime(values[0], this.hass.language);