Transposing an estimated time span into milliseconds (and optionally humanizing the duration using moment.js).

Calculate Duration

/**
 * @param etaTime Integer
 * @param etaScope String
 * @param True/False/Boolean
 **/

function calculateDuration(etaTime, etaScope, humanize) {
	if (typeof etaTime !== 'number') {
		etaTime = parseInt(etaTime, 10);
	}
	var multiplier, combinedTime,
	millisecond = 1,
	second = millisecond * 1000,
	minute = (second * 60),
	hour = (minute * 60),
	day = (hour * 24),
	week = (day * 7),
	month = (week * 4),
	year = (month * 12);
	if (etaScope === ('minutes' || 'minute')) {
		multiplier = minute;
	}
	else if (etaScope === ('hours' || 'hour')) {
		multiplier = hour;
	}
	else if (etaScope === ('days' || 'day')) {
		multiplier = day;
	}
	else if (etaScope === ('weeks' || 'week')) {
		multiplier = week;
	}
	else if (etaScope === ('months' || 'month')) {
		multiplier = month;
	}
	else {
		multiplier = year;
	}
	if (humanize) {
		combinedTime = moment.humanizeDuration(etaTime * multiplier);
	}
	else {
		combinedTime = etaTime * multiplier;
	}
	return combinedTime;
}