js时间戳格式化

//格式化时间戳
function formatTimestamp(dateTime,isShowTime){

if(dateTime==null || dateTime==""){
return "";
}
var date = new Date(dateTime);
var time = "";
var year = "";
var day = "";
var month = date.getMonth()+1;
month = month<10?("0"+month):month;
//Mon May 21 15:04:36 CST 2018
if(dateTime.toString().indexOf("CST")!=-1){
var arr = dateTime.split(" ");
year = arr[5];
time= arr[3];
day = arr[2];
}else if(date.toString().indexOf("GMT")!=-1){//Sun May 20 2018 10:12:13 GMT+0800 (中国标准时间)
var arr = date.toString().split(" ");
    year = arr[3];
time= arr[4];
day = arr[2];
}
var reDate = year+"-"+month+"-"+day;
    //显示时间
    if(isShowTime){
    reDate += " " +time;
    }
    
    return reDate;
}