Year | Month
2012 | 12
2013 | 01
2013 | 02
2013 | 03

Year | Month
2012 | 12
2013 | 01
2013 | 02
2013 | 03
2012 | 12
2013 | 01
2013 | 02
2013 | 03
2012 | 12
2013 | 01
2013 | 02
2013 | 03

function output(range,amount,header) {
  var output = [];

  // check if range is cell
  if(typeof range == 'string') {
    for(var i=0; i<amount; i++) {
      output.push([range]);
    }
    return output;
  } else {
    // check if header is wanted
    var value;
    if(header == 1) {
      output.push(range[0]);
      value=header;
    } else if(header == "") {
      value=0;
    } else {
      value=0;
    }
    for(var i=0; i<amount; i++) {
      for(var j=value, jLen=range.length; j<jLen; j++) {
        output.push(range[j]);
      }
    }
    return output;
  }
}