seconds to years, or months, or days, or hours, or mintues

function convert(seconds) {
  //var hours = Math.floor(seconds / (60*60));
  //seconds %= (60*60);
  //var minutes = Math.floor(seconds / 60);
  //seconds %= 60;
  //var seconds = seconds; 
  var d = Math.floor(seconds / (3600*24));
  var h = Math.floor(seconds % (3600*24) / 3600);
  var m = Math.floor(seconds % 3600 / 60);
  var s = Math.floor(seconds % 60);

  var dDisplay = d > 0 ? d + (d == 1 ? " day, " : " days, ") : "";
  var hDisplay = h > 0 ? h + (h == 1 ? " hour, " : " hours, ") : "";
  var mDisplay = m > 0 ? m + (m == 1 ? " minute, " : " minutes, ") : "";
  var sDisplay = s > 0 ? s + (s == 1 ? " second" : " seconds") : "";