function dateFormatter(date) {
        //YYYY-MM-DD
        var year = date.getUTCFullYear();
        var month = date.getUTCMonth();
        month++; // months begin at 0 for some reason
        if (month < 10) {
                month = "0" + month; // add a leading 0
        }
        var day = date.getUTCDate()
        if (day < 10) {
                day = "0" + day; // add a leanding 0
        }

        return year + "-" + month + "-" + day; // return in YYYY-MM-DD format
}


var today = new Date();
console.log(dateFormatter(today)); // Display today

var yesterday = new Date();
yesterday.setDate(yesterday.getDate() - 1);
console.log(dateFormatter(yesterday)); // Display yesterday

// Display last 30 days, notice that date math is correct, minusing the month at the appropriate point
var aDate = new Date();
for (var i = 30; i > 0; i--) {
        aDate.setDate(aDate.getDate() - 1);
        console.log(dateFormatter(aDate));
}