feat(Calendar): add unselect event (#6198)

src/calendar/utils.ts

@@ -57,6 +57,10 @@ export function calcDateNum(date: [Date, Date]) {
   return (day2 - day1) / (1000 * 60 * 60 * 24) + 1;
 }
 
+export function copyDate(dates: Date) {
+  return new Date(dates);
+}
+
 export function copyDates(dates: Date | Date[]) {
   if (Array.isArray(dates)) {
     return dates.map((date) => {
@@ -64,9 +68,9 @@ export function copyDates(dates: Date | Date[]) {
         return date;
       }
 
-      return new Date(date);
+      return copyDate(date);
     });
   }
 
-  return new Date(dates);
+  return copyDate(dates);
 }