code: function(offset) {
  			offset = offset || 0
  			var year = this.year
  
  			var monthNum = this.month
  			monthNum += offset
  			if(monthNum < 0) { year-- }
  			if(monthNum > 11) { year++ }
  			
  			return year
  		}
docs: Returns the year based on month offset
  The year only changes if the month wraps to the next year
  @param integer month offset