formatDays.js

formatDays = function (d) {
  var days = Math.floor(d / 86400),
    hours = Math.floor((d - (days * 86400)) / 3600),
    minutes = Math.floor((d - (days * 86400) - (hours * 3600)) / 60),
    seconds = d - (days * 86400) - (hours * 3600) - (minutes * 60);
  var output = '';
  if (seconds) {
    output = seconds + 's';
  }
  if (minutes) {
    output = minutes + 'm ' + output;
  }
  if (hours) {
    output = hours + 'h ' + output;
  }
  if (days) {
    output = days + 'd ' + output;
  }
  return output;
};