if (updateFilters)
{
    var timeRE = /^([01]\d|2[0123])(:[0-5]\d:[0-5]\d)$/;
    
    function convertGMTToBritishTime(time)
    {
        var m = timeRE.exec(time);
        if (m == null)
            return "-";
        if (m[1].indexOf("0") == 0)
            m[1] = m[1].substring(1);
        var hour = parseInt(m[1]);
        hour = (hour + summerOffset) % 24;
        if (hour < 10)
            hour = "0" + hour;
        return hour + m[2];
    }
    
    function checkSymbol(symbol)
    {
        // only derivatives needs to be updated
        if (/^.*?\d{2}.*?\.LI$/.test(symbol)) // so *07*.LI
            return true;
        return false;
    }
    
    updateFilters.addFilter(checkSymbol, /TT/, null, convertGMTToBritishTime);
}