JSFiddle - React, Tailwind, and code Playground

JavaScript

function getFridays(month, year){
    var ret = [];
    for(var i = 1; i <= 31; i++){
        var date = new Date();
        date.setDate(i);
        date.setMonth(month - 1);
        date.setFullYear(year);
        if(date.getDay() === 5){
            var today = date.getDate() + '/' + (date.getMonth() + 1) + '/' + date.getFullYear();
            ret.push(today);
            
        }
    }
    return ret;
}

document.write(getFridays(12, 2011));