Get the date for Monday and Friday of the current week, with JS.

getMondayAndFriday.js

function getMonday() {
    d = new Date();
    var day = d.getDay(),
        diff = d.getDate() - day + (day == 0 ? -6 : 1);
    return new Date(d.setDate(diff));
}

function getFriday() {
    let monday = getMonday();
    return new Date(monday.setDate(monday.getDate() + 4));
}

console.log(getMonday());
console.log(getFriday());