.x-datepicker-weeknumber-header {
    width: 23px;
    text-align: center;
    font-size: 11px;
    color: #999;
    padding: 0 2px;
    border-right: 1px solid #e0e0e0;
}

.x-datepicker-weeknumber {
    text-align: center;
    font-size: 11px;
    color: #999;
    padding: 2px 2px;
    border-right: 1px solid #e0e0e0;
    cursor: default;
}