convert minutes integer into hour string.

minutesToHours.js

//usage
//minutesToHours(60) = '1:00'
//minutesToHours(45) = '0:45'
//minutesToHours(43) = '0:45'  rounds to nearest 15
function minutesToHours(minutes){
	var isNegative = (minutes < 0);
	var absMinutes = Math.abs(minutes); //if negative convert to positive
	var dividedBy60 = (absMinutes / 60);
	var roundedHour = Math.floor(dividedBy60);
	var minutesLeft = (absMinutes % 60);
	var roundedMinutes = roundMinutes(minutesLeft, 15);  //nearest 15
	var resultMinutes;
	var result;

	if(minutesLeft > 30 && roundedMinutes === 0){
		roundedHour = roundedHour + 1;
		resultMinutes = "00";

	} else {
		resultMinutes = roundedMinutes.toString();
		//prepend leading "0"
		if(resultMinutes.length === 1){
			resultMinutes = "0" + resultMinutes;
		}
	}

	result = (roundedHour).toString() + ":" + resultMinutes;
	
	if(isNegative){
		result = "-" + result;
	}

	return result;

	function roundMinutes(minutes, roundMinutesTo){
		var midPoint = (roundMinutesTo / 2);
		return ( ( ( ( (minutes + midPoint) / roundMinutesTo) | 0 ) * roundMinutesTo) % 60);
	}
}