diff --git a/js/component/card/runtime_thermostat_summary.js b/js/component/card/runtime_thermostat_summary.js
index fd670b8..fe4c6c6 100755
--- a/js/component/card/runtime_thermostat_summary.js
+++ b/js/component/card/runtime_thermostat_summary.js
@@ -181,10 +181,7 @@ beestat.component.card.runtime_thermostat_summary.prototype.get_data_ = function
 
   var begin_m;
   if (beestat.setting('runtime_thermostat_summary_time_period') === 'all') {
-    begin_m = moment.min(
-      moment(beestat.cache.thermostat[this.thermostat_id_].data_begin),
-      moment(beestat.cache.thermostat[this.thermostat_id_].first_connected)
-    );
+    begin_m = moment(beestat.cache.thermostat[this.thermostat_id_].sync_begin);
   } else {
     var time_periods = [
       'day',