Fix time selector + base am/pm on user language (#8908)

Co-authored-by: Paulus Schoutsen <balloob@gmail.com>

src/components/ha-selector/ha-selector-time.ts

@@ -1,12 +1,9 @@
 import { customElement, html, LitElement, property } from "lit-element";
+import memoizeOne from "memoize-one";
 import { fireEvent } from "../../common/dom/fire_event";
 import { TimeSelector } from "../../data/selector";
 import { HomeAssistant } from "../../types";
 import "../paper-time-input";
-
-const test = new Date().toLocaleString();
-const useAMPM = test.includes("AM") || test.includes("PM");
-
 @customElement("ha-selector-time")
 export class HaTimeSelector extends LitElement {
   @property() public hass!: HomeAssistant;
@@ -19,16 +16,24 @@ export class HaTimeSelector extends LitElement {
 
   @property({ type: Boolean }) public disabled = false;
 
+  private _useAmPm = memoizeOne((language: string) => {
+    const test = new Date().toLocaleString(language);
+    return test.includes("AM") || test.includes("PM");
+  });
+
   protected render() {
+    const useAMPM = this._useAmPm(this.hass.locale.language);
+
     const parts = this.value?.split(":") || [];
-    const hours = useAMPM ? parts[0] ?? "12" : parts[0] ?? "0";
+    const hours = parts[0];
 
     return html`
       <paper-time-input
         .label=${this.label}
-        .hour=${useAMPM && Number(hours) > 12 ? Number(hours) - 12 : hours}
-        .min=${parts[1] ?? "00"}
-        .sec=${parts[2] ?? "00"}
+        .hour=${hours &&
+        (useAMPM && Number(hours) > 12 ? Number(hours) - 12 : hours)}
+        .min=${parts[1]}
+        .sec=${parts[2]}
         .format=${useAMPM ? 12 : 24}
         .amPm=${useAMPM && (Number(hours) > 12 ? "PM" : "AM")}
         .disabled=${this.disabled}
@@ -42,12 +47,16 @@ export class HaTimeSelector extends LitElement {
 
   private _timeChanged(ev) {
     let value = ev.target.value;
-    if (useAMPM) {
-      let hours = Number(ev.target.hour);
+    const useAMPM = this._useAmPm(this.hass.locale.language);
+    let hours = Number(ev.target.hour || 0);
+    if (value && useAMPM) {
       if (ev.target.amPm === "PM") {
         hours += 12;
       }
-      value = `${hours}:${ev.target.min}:${ev.target.sec}`;
+      value = `${hours}:${ev.target.min || "00"}:${ev.target.sec || "00"}`;
+    }
+    if (value === this.value) {
+      return;
     }
     fireEvent(this, "value-changed", {
       value,

src/components/paper-time-input.js

@@ -133,7 +133,7 @@ export class PaperTimeInput extends PolymerElement {
           always-float-label$="[[alwaysFloatInputLabels]]"
           disabled="[[disabled]]"
         >
-          <span suffix="" slot="suffix">:</span>
+          <span suffix slot="suffix">:</span>
         </paper-input>
 
         <!-- Min Input -->
@@ -303,28 +303,28 @@ export class PaperTimeInput extends PolymerElement {
         notify: true,
       },
       /**
-       * Suffix for the hour input
+       * Label for the hour input
        */
       hourLabel: {
         type: String,
         value: "",
       },
       /**
-       * Suffix for the min input
+       * Label for the min input
        */
       minLabel: {
         type: String,
-        value: ":",
+        value: "",
       },
       /**
-       * Suffix for the sec input
+       * Label for the sec input
        */
       secLabel: {
         type: String,
         value: "",
       },
       /**
-       * Suffix for the milli sec input
+       * Label for the milli sec input
        */
       millisecLabel: {
         type: String,