Как получить дату ближайшей субботы?

function getSaturday() {
    var today = new Date().getUTCDay();
    var diff = 6 - today;
    if ([-1, 0].includes(Math.sign(diff))) {
        return new Date(new Date().setUTCDate(13 - today));
    }
    return new Date(new Date().setUTCDate(diff));
}