자바스크립트 날짜 차이 계산

const startDt = new Date ('2022-11-10');
const endDt =  new Date ('2022-11-20');
const dateCondition  = (startDt,endDt) =>{
        let btMs = endDt.getTime() - startDt.getTime() ;
        let btDay = btMs / (1000*60*60*24) ;
        return btDay;
}