百度了N次，说db.serverDate()创建的时间。无法在WXML中解析？

wxs时间格式化页面时间是正常的，格式化服务器的时间就显示NaN,百度上查很多，有的说，db.serverDate()创建的时间，在wxml中无法解析。怎么解决？

wxs代码：

var timeFormat = function(time){
  console.log(time);
  var date = getDate(time);
  console.log(date);
  var date_seconds = date.getTime() / 1000;
  var now = getDate();
  var now_seconds = now.getTime() / 1000;
  var timestamp = now_seconds - date_seconds;
  var timeStr = "";
  if(timestamp < 60){
    timeStr = "刚刚";
  }else if(timestamp >= 60 && timestamp < 60 * 60){
    var minutes = parseInt(timestamp / 60);
    timeStr = minutes + "分钟前";
  }else if(timestamp >= 60 * 60 && timestamp < 60 * 60 * 24){
    var hours = parseInt(timestamp / 60 / 60);
  timeStr = hours + "小时前";
  }else if(timestamp >= 60 * 60 * 24 && timestamp < 60 * 60 * 24 * 30){
    var days = parseInt(timestamp / 60 / 60 / 24);
    timeStr = days + "天前";
  }else{
    var year = date.getFullYear();
    var month = date.getMonth();
    var day = date.getDate();
    var hour = date.getHours();
    var minute = date.getMinutes();
    timeStr = year + "/" + month + "/" + day + " " + hour + ":" + minute;
  }
  return timeStr;
}
module.exports={
  timeFormat:timeFormat,
}