From a54107aeb522aba24ab75bfac32596f0dcb82962 Mon Sep 17 00:00:00 2001
From: Zack Arnett <arnett.zackary@gmail.com>
Date: Tue, 29 Sep 2020 22:37:15 -0500
Subject: [PATCH 1/3] Update events on config change

---
 .../lovelace/cards/hui-calendar-card.ts       | 23 +++++++++++++++----
 1 file changed, 18 insertions(+), 5 deletions(-)

diff --git a/src/panels/lovelace/cards/hui-calendar-card.ts b/src/panels/lovelace/cards/hui-calendar-card.ts
index eb55d3d43504..330dcc2ca092 100644
--- a/src/panels/lovelace/cards/hui-calendar-card.ts
+++ b/src/panels/lovelace/cards/hui-calendar-card.ts
@@ -71,6 +71,10 @@ export class HuiCalendarCard extends LitElement implements LovelaceCard {
 
   @internalProperty() private _veryNarrow = false;
 
+  private _startDate?: Date;
+
+  private _endDate?: Date;
+
   private _resizeObserver?: ResizeObserver;
 
   public setConfig(config: CalendarCardConfig): void {
@@ -90,6 +94,7 @@ export class HuiCalendarCard extends LitElement implements LovelaceCard {
     });
 
     this._config = { initial_view: "dayGridMonth", ...config };
+    this._fetchCalendarEvents();
   }
 
   public getCardSize(): number {
@@ -152,13 +157,21 @@ export class HuiCalendarCard extends LitElement implements LovelaceCard {
     }
   }
 
-  private async _handleViewChanged(
-    ev: HASSDomEvent<CalendarViewChanged>
-  ): Promise<void> {
+  private _handleViewChanged(ev: HASSDomEvent<CalendarViewChanged>): void {
+    this._startDate = ev.detail.start;
+    this._endDate = ev.detail.end;
+    this._fetchCalendarEvents();
+  }
+
+  private async _fetchCalendarEvents(): Promise<void> {
+    if (!this._startDate || !this._endDate) {
+      return;
+    }
+
     this._events = await fetchCalendarEvents(
       this.hass!,
-      ev.detail.start,
-      ev.detail.end,
+      this._startDate,
+      this._endDate,
       this._calendars
     );
   }

From eb1b2b33d32da11f557bd415a95f9a92b0c4c43a Mon Sep 17 00:00:00 2001
From: Zack Arnett <arnett.zackary@gmail.com>
Date: Tue, 29 Sep 2020 22:38:28 -0500
Subject: [PATCH 2/3] only fetch if entities changed

---
 src/panels/lovelace/cards/hui-calendar-card.ts | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/panels/lovelace/cards/hui-calendar-card.ts b/src/panels/lovelace/cards/hui-calendar-card.ts
index 330dcc2ca092..3d23c09cb5ef 100644
--- a/src/panels/lovelace/cards/hui-calendar-card.ts
+++ b/src/panels/lovelace/cards/hui-calendar-card.ts
@@ -93,8 +93,11 @@ export class HuiCalendarCard extends LitElement implements LovelaceCard {
       };
     });
 
+    if (this._config.entities !== config.entities) {
+      this._fetchCalendarEvents();
+    }
+
     this._config = { initial_view: "dayGridMonth", ...config };
-    this._fetchCalendarEvents();
   }
 
   public getCardSize(): number {

From 7f61443b3c7ff02473e2d826f06e6386b2d1bff7 Mon Sep 17 00:00:00 2001
From: Zack Arnett <arnett.zackary@gmail.com>
Date: Tue, 29 Sep 2020 22:38:46 -0500
Subject: [PATCH 3/3] undefined check

---
 src/panels/lovelace/cards/hui-calendar-card.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/panels/lovelace/cards/hui-calendar-card.ts b/src/panels/lovelace/cards/hui-calendar-card.ts
index 3d23c09cb5ef..625e915fac98 100644
--- a/src/panels/lovelace/cards/hui-calendar-card.ts
+++ b/src/panels/lovelace/cards/hui-calendar-card.ts
@@ -93,7 +93,7 @@ export class HuiCalendarCard extends LitElement implements LovelaceCard {
       };
     });
 
-    if (this._config.entities !== config.entities) {
+    if (this._config?.entities !== config.entities) {
       this._fetchCalendarEvents();
     }