JavaScirpt: some helper functions with moment.js

momentHelper.js

/*
  @param
  date: '2014-01'
  @return
  '2014-02'
*/
function getNextMonth(date){
  var current = moment(date).month();
  return moment(date).month(current + 1).format("YYYY-MM");
}

/*
  @param
  date: '2014-01'
  @return
  '2013-12'
*/
function getPreviousMonth(date){
  var current = moment(date).month();
  return moment(date).month(current - 1).format("YYYY-MM");
}