Make sure component always returns midnight utc.

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@tp/tp-date-picker",
-  "version": "3.0.0",
+  "version": "3.0.2",
   "description": "",
   "main": "tp-date-picker.js",
   "scripts": {

tp-date-picker.js

@@ -220,6 +220,7 @@ class TpDatePicker extends FormElement(LitElement) {
       yearsBackwards: { type: Number },
       showYearSelector: { type: Boolean },
       events: { type: Array },
+      timeZone: { type: String }, // User's timezone for date interpretation
     };
   }
 
@@ -289,7 +290,10 @@ class TpDatePicker extends FormElement(LitElement) {
     for (const el of e.composedPath()) {
       if (el.date !== undefined) {
         this.value = el.date;
-        this.dispatchEvent(new CustomEvent('value-changed', { detail: this.value, bubbles: true, composed: true }));
+        const selectedDate = el.date;
+        // Date-only fields always store UTC midnight — the calendar date is timezone-agnostic.
+        const outputValue = DateTime.utc(selectedDate.year, selectedDate.month, selectedDate.day).toISO();
+        this.dispatchEvent(new CustomEvent('value-changed', { detail: outputValue, bubbles: true, composed: true }));
         return;
       }
     }