time_as_relative

time_as_relative.js

function time_as_relative(t1,t2,fix){
  var diff = t1 - t2;
  var minute = 60, hour = minute * 60, day = hour * 24, 
  week = day * 7, month = day * 30, year = month * 12;
  return in_range(
    [0,'just now'],
    [5,'% seconds',1],
    [minute,'a minute'],
    [minute*2,'% minutes',minute],
    [minute*30,'half an hour'],
    [minute*31,'% minutes',minute],
    [hour,'an hour'],
    [hour*2,'% hours',hour],
    [hour*3,'a few hours'],
    [hour*4,'% hours',hour],
    [day,'a day'],
    [day*2,'% days',day],
    [week,'a week'],
    [week*2,'% weeks',week],
    [month,'a month'],
    [month*2,'% months',month],
    [year,'a year'],
    [year*2,'% years',year]
  );
  function in_range() {
    var span = Math.abs(diff/1000);
    for (var i = arguments.length-1; i >= 0; i--) {
      var range = arguments[i];
      if (span >= range[0]) {
        return (
          (fix&& diff>0?'in ':'') +
            (range[1].match(/%/)? 
             range[1].replace(/%/g,Math.round(span/(range[2]? range[2] : 1)))
             : range[1]) +
            (fix&& diff<0?' ago':'')
        );
      }
    }
  }
}