js如何实现获取0点的时间戳

// 获取0点的时间戳
function getTimes(day){
    let times=new Date(new Date().setHours(0,0,0,0)-day*24*60*60*1000)
    return times*1
}
// day为往前day天
// 获取今天的传0
let timesDay1=this.getTimes(0)
console.log(timesDay1);