This is a jQuery utility method I wrote that takes a number representing the number of months and returns a string representation of that number in years and months.

Months to Years

$.monthsToYears = function(months){
  var val;
	if(months < 12) {
		val = months + ' month';
		if(months > 1 || months === 0){
			val += 's';
		}
	} else {
		var yrs = Math.floor(months/12);
		var mo = months%12;
		val = yrs + ' year';
		if(yrs > 1){
			val += 's';
		}
		if(mo != 0){
			val += ' ' + mo + ' month';
		}
		if(mo > 1){
			val += 's';
		}		
	}
	return val;
};