code: function(start, end) {
      var date;
      var res = [];
      for (var key in holidays) {
        date = beginningOfDay(new Date(key));
        // given `start` and `end` Date object are both normalized to beginning of the day
        if (beginningOfDay(start) <= date && date <= beginningOfDay(end)) {
          res.push(holiday(date, holidays[key]));
        }
      }
      return res;
    }
docs: Find holidays between `start` and `end`.
  
  @param {Date} start
  @param {Date} end
  @return {Array[Object]}
  @api public