SVY-20592 Date Picker shows Invalid DateTime

refactor date validation to improve accuracy

Author: cPecican

components/projects/bootstrapcomponents/src/calendar/calendar.ts

@@ -137,15 +137,15 @@ export class ServoyBootstrapCalendar extends ServoyBootstrapBaseCalendar {
             super.pushUpdate();
         }
 
-		if ((event !== '' && ((this.minDate && this.minDate > event) || (this.maxDate && this.maxDate < event))) ||
-        /* 2024.12 fix */        
-        event === undefined ||
-        /* lts_latest fix */
-        event.toString() === 'Invalid Date') {
+		if ((event !== '' && ((this.minDate && this.minDate > event) || (this.maxDate && this.maxDate < event))) || !this.isValidDate(event)) {
 			// revert to old value
 			this.svyFormat.writeValue(this.dataProviderID);
 		}
     }
+    
+    isValidDate(date: any): boolean {
+        return date instanceof Date && !isNaN(date.getTime());
+    }
 
     public getNativeChild(): any {
         return this.inputElementRef.nativeElement;