Javascript: return 7 days in order with today first

weekdays-from-today.js

//returns 7 day names with today first
function startday() {
    var days = ['Sun','Mon','Tue','Wed','Thu','Fri','Sat'];
    var today = new Date();
    var start = today.getDay(); //gets day number
    if (start == 0) { //if Sunday, days are in order
        return days
    }
    else { //if not Sunday, start days with today
        return days.slice(start).concat(days.slice(0,start))
    }
}