获取时间00:00:00-23:59:59

const start = new Date(new Date(new Date().toLocaleDateString()).getTime()); 
console.log(start); //Mon Dec 04 2017 00:00:00 GMT+0800 (中国标准时间)

const start = new Date(new Date(new Date().toLocaleDateString()).getTime()+24*60*60*1000-1);
console.log(start); //Mon Dec 04 2017 23:59:59 GMT+0800 (中国标准时间)