diff --git a/js/component/card/runtime_thermostat_summary.js b/js/component/card/runtime_thermostat_summary.js
index 1c4d7b7..fd670b8 100755
--- a/js/component/card/runtime_thermostat_summary.js
+++ b/js/component/card/runtime_thermostat_summary.js
@@ -181,8 +181,9 @@ 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(
-      beestat.cache.thermostat[this.thermostat_id_].data_begin
+    begin_m = moment.min(
+      moment(beestat.cache.thermostat[this.thermostat_id_].data_begin),
+      moment(beestat.cache.thermostat[this.thermostat_id_].first_connected)
     );
   } else {
     var time_periods = [