js 时间转为时间戳

function transdate(endTime){
var date=new Date();
date.setFullYear(endTime.substring(0,4));
date.setMonth(endTime.substring(5,7)-1);
date.setDate(endTime.substring(8,10));
date.setHours(endTime.substring(11,13));
date.setMinutes(endTime.substring(14,16));
date.setSeconds(endTime.substring(17,19));
return Date.parse(date)/1000;
}