Improved EventDateInfo and set date as optional

src/schemas/SemanticTagType.ts

@@ -28,9 +28,8 @@ export const CurrencyAmount = Joi.object<CurrencyAmount>().keys({
  * @see \<undiclosed>
  */
 
-export type EventDateInfo =
-	| {
-			date: string;
+export interface EventDateInfo {
+	date?: string;
 	ignoreTimeComponents?: boolean;
 	timeZone?: string;
 
@@ -41,11 +40,11 @@ export type EventDateInfo =
 	 * Leads to showing "TBA" in the UI when `date` is set.
 	 * Setting `ignoreTimeComponents` to true, has higher priority
 	 * over this property.
+	 *
+	 * When both `date` and `semantics.eventStartDate` are unset,
+	 * `Date: TBA` will be shown in the UI.
 	 */
 	unannounced?: boolean;
-	  }
-	| {
-			date?: string;
 
 	/**
 	 * @iOSVersion 18.1
@@ -57,13 +56,11 @@ export type EventDateInfo =
 	 *
 	 * This property has higher priority over `unannounced`.
 	 *
-			 * --- Implementation note ---
-			 *
-			 * This is the reason it was splitted from unannounced above.
-			 * Furthermore, it apparently can live without specifying `date`.
+	 * When both `date` and `semantics.eventStartDate` are unset,
+	 * `Date: TBD` will be shown in the UI.
 	 */
-			undetermined: boolean;
-	  };
+	undetermined?: boolean;
+}
 
 export const EventDateInfo = Joi.alternatives(
 	Joi.object<EventDateInfo>().keys({