兼容IOS的日期转时间戳

1、日期转时间戳

function datetime_to_unix(datetime){
    var tmp_datetime = datetime.replace(/:/g,'-');
    tmp_datetime = tmp_datetime.replace(/ /g,'-');
    var arr = tmp_datetime.split("-");
    var now = new Date(Date.UTC(arr[0],arr[1]-1,arr[2],arr[3]-8,arr[4],arr[5]));
    return parseInt(now.getTime()/1000);
}
datetime_to_unix('2018-08-08 22:22:22');