function isTimestamp(column, rows) {
    var tsRegExp = new RegExp('^('+year+'-'+mon+'-'+day+' [0-2][0-9]:[0-2][0-9]:[0-2][0-9](\.[0-9]{3})?( [-+]1?[0-9]:[0-5][0-9])?)$');
    return evaluateColumn(column, rows, tsRegExp);
}