function showZeroFilled(inValue) {
    if (inValue > 9) {
        return "" + inValue;
    }
    return "0" + inValue;
}

function prepocet(hod){
    var cas = hod - 3;
    if(cas < 0){
        return 24+cas;
    }
    else {
        return cas;
    }
}

function showTheTime() {
    now = new Date
    document.getElementById("cas").innerHTML = "<span class='cas'>" + prepocet(now.getUTCHours()) + ":" + showZeroFilled(now.getMinutes()) + ":" + showZeroFilled(now.getSeconds()) + "</span><br>Aktuální čas v Kanadě"
    setTimeout("showTheTime()",1000)   
}