gistfile1.js

function calculate(time, num)
	{
		var inte = ["segundo", "minuto", "hora", "día", "semana", "mes", "año"];
		var dur = [60, 60, 24, 7, 4.35, 12];

		time = parseInt(time);
		var now = parseInt( Math.round((new Date()).getTime() / 1000) );
		var j = 0;

		var dif = 0;
		var str = "";

		var sh = time + 10;

		//if(now == time || now < sh)
		//	return "Justo ahora";
		if(now > time)
		{
			dif = now - time;
			str = "Hace";
		}
		else
		{
			dif = time - now;
			str = "Dentro de";
		}

		for(j = 0; dif >= dur[j] && j < dur.length - 1; j++)
			dif /= dur[j];

		dif = Math.round(dif);

		if(dif != 1)
		{
			inte[5] += "e";
			inte[j] += "s";
		}

		if(num == true)
			return dif + ' ' + inte[j];
		else
			return str + " " + dif + " " + inte[j];
	}