diff --git a/src/panels/calendar/dialog-calendar-event-editor.ts b/src/panels/calendar/dialog-calendar-event-editor.ts
index 613a048f7e..043064a300 100644
--- a/src/panels/calendar/dialog-calendar-event-editor.ts
+++ b/src/panels/calendar/dialog-calendar-event-editor.ts
@@ -250,6 +250,7 @@ class DialogCalendarEventEditor extends LitElement {
           <ha-recurrence-rule-editor
             .hass=${this.hass}
             .dtstart=${this._dtstart}
+            .allDay=${this._allDay}
             .locale=${this.hass.locale}
             .timezone=${this.hass.config.time_zone}
             .value=${this._rrule || ""}
diff --git a/src/panels/calendar/ha-recurrence-rule-editor.ts b/src/panels/calendar/ha-recurrence-rule-editor.ts
index 7e10952574..d2965e0284 100644
--- a/src/panels/calendar/ha-recurrence-rule-editor.ts
+++ b/src/panels/calendar/ha-recurrence-rule-editor.ts
@@ -41,6 +41,8 @@ export class RecurrenceRuleEditor extends LitElement {
 
   @property() public dtstart?: Date;
 
+  @property() public allDay?: boolean;
+
   @property({ attribute: false }) public locale!: HomeAssistant["locale"];
 
   @property() public timezone?: string;
@@ -402,7 +404,14 @@ export class RecurrenceRuleEditor extends LitElement {
       byweekday: byweekday,
       bymonthday: bymonthday,
     };
-    const contentline = RRule.optionsToString(options);
+    let contentline = RRule.optionsToString(options);
+    if (this._until && this.allDay) {
+      // rrule.js only computes UNTIL values as DATE-TIME however rfc5545 says
+      // The value of the UNTIL rule part MUST have the same value type as the
+      // "DTSTART" property. If needed, strip off any time values as a workaround
+      // This converts "UNTIL=20220512T060000" to "UNTIL=20220512"
+      contentline = contentline.replace(/(UNTIL=\d{8})T\d{6}Z?/, "$1");
+    }
     return contentline.slice(6); // Strip "RRULE:" prefix
   }