es: {
      year: function(c) { return "año" + ((c !== 1) ? "s" : ""); },
      month: function(c) { return "mes" + ((c !== 1) ? "es" : ""); },
      week: function(c) { return "semana" + ((c !== 1) ? "s" : ""); },
      day: function(c) { return "día" + ((c !== 1) ? "s" : ""); },