기간 설정하여 검색 후 2페이지 눌렀을때 날짜가 1970년 1월1일로 바뀌는 현상

$sql = " SELECT * FROM g5_write_sub03_02 where wr_is_comment = 0 and wr_6 <> '완료' ";

if($member['mb_level']=='10'){

    $sql_where ="";

}else if($member['mb_level']=='7'){

    $sql_where =" and wr_subject = '".$member['mb_4']."' ";

}else if($member['mb_level']=='5'){

    $sql_where =" and wr_subject = '".$member['mb_4']."' and wr_5 = '".$member['mb_nick']."' ";

}

if($_GET['sfl']){

    $sfl = mysql_escape_string($_GET['sfl']);

    $stx = mysql_escape_string($_GET['stx']);

    $sql_sch = " and ".$sfl." like '".$stx."%' ";

}

if($_GET['wr_1']) {

$wr_2 = mysql_escape_string($_GET['start_y']."-".$_GET['start_m']."-".$_GET['start_d']);

$wr_3 = mysql_escape_string($_GET['end_y']."-".$_GET['end_m']."-".$_GET['end_d']);

$wr_2 = date("Y-m-d", strtotime($wr_2));

$wr_3 = date("Y-m-d", strtotime($wr_3));

$sql_search = " and (wr_1 between '$wr_2' and '$wr_3') ";

}else{

$wr_2 = date("Y-m-d");

$wr_3 = date("Y-m-d");

}

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$date_paging = "&amp;sfl=".$sfl."&amp;stx=".urlencode($stx)."&amp;wr_1=".$_GET['wr_1']."&amp;start_y=".mktime($_GET['start_y']."&amp;start_m=".$_GET['start_m']."&amp;start_d".$_GET['start_d'])."&amp;end_y=".($_GET['end_y']."&amp;end_m=".$_GET['end_m']."&amp;end_d=".$_GET['end_d']); 

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기간 검색 후에 1페이지는 날짜가 그대로 유지되어 있지만

2페이지로 넘어가면 사진처럼 날짜가 바뀌어 버립니다.

해결방법이 있을까요?