function getWeek(year,month,day){
    var a = Math.floor((14-(month))/12);
    var y = year+4800-a;
    var m = (month)+(12*a)-3;
    var jd = day + Math.floor(((153*m)+2)/5) + (365*y) + Math.floor(y/4) - Math.floor(y/100) + Math.floor(y/400) - 32045;
    var d4 = (jd+31741-(jd%7))%146097%36524%1461;
    var L = Math.floor(d4/1460);
    var d1 = ((d4-L)%365)+L;
    NumberOfWeek = Math.floor(d1/7) + 1;
    return NumberOfWeek;        
}

var today = new Date();
document.write("<b>Regiojournaal week " + getWeek(today.getYear(),today.getMonth()+1,today.getDate()) + "</b><br>")