66라인부터

---------------------------------------------------------------------------------
(위 라인제거)

// 해당월의 1일
$mktime = mktime(0,0,0,$mm,1,$yyyy);
$dt = getdate(strtotime(date("Y-m-1", $mktime)));

$dt[wday] = $spacer;

// 해당월의 마지막 날짜,
//$last_day = date("t", $mktime);
$last_day = $endday[$mm];

$yyyy_before = $yyyy;
$mm_before = $mm - 1;
if ($mm_before < 1)
{
    $yyyy_before--;
    $mm_before = 12;
}

$yyyy_after = $yyyy;
$mm_after = $mm + 1;
if ($mm_after > 12)
{
    $yyyy_after++;
    $mm_after = 1;
}

$fr_yyyy = $yyyy - 80;
$to_yyyy = $yyyy + 80;

$yyyy_before_href = "$_SERVER[PHP_SELF]?yyyy=".($yyyy-1)."&mm={$mm}&cur_date={$cur_date}&fld={$fld}&delimiter={$delimiter}";
$yyyy_after_href = "$_SERVER[PHP_SELF]?yyyy=".($yyyy+1)."&mm={$mm}&cur_date={$cur_date}&fld={$fld}&delimiter={$delimiter}";

$mm_after_href = "$_SERVER[PHP_SELF]?yyyy={$yyyy_after}&mm={$mm_after}&cur_date={$cur_date}&fld={$fld}&delimiter={$delimiter}";
$mm_before_href = "$_SERVER[PHP_SELF]?yyyy={$yyyy_before}&mm={$mm_before}&cur_date={$cur_date}&fld={$fld}&delimiter={$delimiter}";

$yyyy_select = "<select name=yyyy onchange='document.fcalendar.submit();'>";
for ($i=$fr_yyyy; $i<=$to_yyyy; $i++)
{
    if ($i == $yyyy) $selected = " selected";
    else $selected = "";
    $yyyy_select .= "<option value='{$i}'{$selected}>$i 년</option>";
}
$yyyy_select .= "</select>";

$mm_select = "<select name=mm onchange='document.fcalendar.submit();'>";
for ($i=1; $i<=12; $i++)
{
    if ($i == $mm) $selected = " selected";
    else $selected = "";
    $mm_select .= "<option value='{$i}'{$selected}>$i 월</option>";
}
$mm_select .= "</select>";

$member_skin_path = "$g4[path]/skin/member/$config[cf_member_skin]";
include_once("$member_skin_path/calendar.skin.php");
?>

<script type="text/javascript">
//
// year : 4자리
// month : 1~2자리
// day : 1~2자리
// wday : 요일 숫자 (0:일 ~ 6:토)
// handay : 요일 한글
//
function date_send(year, month, day, wday, handay)
{
    var delimiter = document.getElementById('delimiter').value;
    opener.document.getElementById('<?=$fld?>').value = year + delimiter + month + delimiter + day;
    window.close();
}
</script>

<?
include_once("$g4[path]/tail.sub.php");
?>

------------------------------------------------------------------------
(위 라인제거)

이렇게 바꿔보세요.