diff --git a/src/components/ha-dialog-date-picker.ts b/src/components/ha-dialog-date-picker.ts
index b39df2f879..2422754cfb 100644
--- a/src/components/ha-dialog-date-picker.ts
+++ b/src/components/ha-dialog-date-picker.ts
@@ -1,5 +1,6 @@
 import "@material/mwc-button/mwc-button";
 import "app-datepicker";
+import { format } from "date-fns";
 import { css, html, LitElement, nothing } from "lit";
 import { customElement, property, state } from "lit/decorators";
 import { fireEvent } from "../common/dom/fire_event";
@@ -66,11 +67,16 @@ export class HaDialogDatePicker extends LitElement {
   }
 
   private _setToday() {
-    // en-CA locale used for date format YYYY-MM-DD
-    this._value = new Date().toLocaleDateString("en-CA");
+    const today = new Date();
+    this._value = format(today, "yyyy-MM-dd");
   }
 
   private _setValue() {
+    if (!this._value) {
+      // Date picker opens to today if value is undefined. If user click OK
+      // without changing the date, should return todays date, not undefined.
+      this._setToday();
+    }
     this._params?.onChange(this._value!);
     this.closeDialog();
   }
diff --git a/src/components/ha-selector/ha-selector-datetime.ts b/src/components/ha-selector/ha-selector-datetime.ts
index 327122b92a..94d4ad9e04 100644
--- a/src/components/ha-selector/ha-selector-datetime.ts
+++ b/src/components/ha-selector/ha-selector-datetime.ts
@@ -45,7 +45,7 @@ export class HaDateTimeSelector extends LitElement {
         </ha-date-input>
         <ha-time-input
           enable-second
-          .value=${values?.[1] || "0:00:00"}
+          .value=${values?.[1] || "00:00:00"}
           .locale=${this.hass.locale}
           .disabled=${this.disabled}
           .required=${this.required}
@@ -60,9 +60,11 @@ export class HaDateTimeSelector extends LitElement {
 
   private _valueChanged(ev: CustomEvent): void {
     ev.stopPropagation();
-    fireEvent(this, "value-changed", {
-      value: `${this._dateInput.value} ${this._timeInput.value}`,
-    });
+    if (this._dateInput.value && this._timeInput.value) {
+      fireEvent(this, "value-changed", {
+        value: `${this._dateInput.value} ${this._timeInput.value}`,
+      });
+    }
   }
 
   static styles = css`