Mohon pencerahan untuk menampilkan tanggal jatuh tempo

Assalam, 
 
 
Berikut koding beserta gambar yang saya tampilkan. 
 
index.php
 
<h4 style='padding-top:15px'>Hasil Input Data Karyawan </h4>
            <!-- Basic Data Tables Example -->
            <div class="col-md-17">
            <div class="paccanel panel-default">
                <div class="panel-heading">
                    <a class='btn btn-primary' href='index.php?view=kegiatan&act=tambah'><i class='fa fa-plus'>
 
 
 
                    </i> Tambahkan Data Baru</a>
                </div>
 
 
                <div class="panel-body">
                 <table class="table table-striped table-bordered table-hover dataTables-example" >
                    <thead class='alert-info'>
                    <tr>
                        <th width='20'>No</th>
                        <th width="50">No. Reg</th>
                        <th width="30">NIK</th>
                        <th width="40">Nama</th>
                        <th width="69">Tanggal Pengajuan</th>
                        <th width="53">Jabatan</th>
                        <th width="83">Departemen</th>
                        <th width="80">Masa Simper</th>
                        <th width="70">Jatuh Tempo(60 hari)</th>
                      	<th width="44">Selisih</th>
                        <th width="47">Status Simper</th>
                      	<th width="40">Action</th>
                    </tr>
                    </thead>
                    <tbody>
 
 
 <?php 
 date_default_timezone_get('Asia/Jakarta');
 $tanggal_now = date('Y-m-d');
 $jatuh_tempo = mktime(0,0,0,date('m'),date('d')+60,date('Y')); // angka 2,7,1 yang dicetak tebal bisa dirubah rubah
 $tambah = date('Y-m-d',$tambah_tanggal);						 		
 $kegiatan = mysql_query("SELECT * FROM data_karyawan ORDER BY noreg_simper DESC");
 
			$no = 1;	
	while ($i = mysql_fetch_array($kegiatan))
 
{
 
echo 
 
"<tr class='gradeX'>
 
<td>$no</td>
<td>$i[noreg_simper]</td>
<td align=center>$i[nik]</td>
<td>$i[nama]</td>
<td>$i[tgl_pengajuan]</td>
<td>$i[jabatan]</td>
<td>$i[departemen]</td>
<td>$i[masa_simper]</td>								
<td>$i[jatuh_tempo]</td>
<td>$i[selisih] hari</td>
<td>$i[status_simper]</td>
 
<td style='width:90px'><center>
<a style='margin-right:10px' href='index.php?view=kegiatan&act=detail&id=$i[noreg_simper]' title='Lihat Detail Data ini'><i class='fa fa-search'></i></a>
                                     <a style='margin-right:10px' href='index.php?view=kegiatan&act=edit&id=$i[nik]' title='Edit Data ini'><i class='fa fa-pencil-square-o'></i></a>
                                     <a href='index.php?view=kegiatan&delete=$i[nik]' title='Hapus Data ini' onclick=\"return confirm('Apakah anda Yakin Data ini Dihapus?')\" ><i class='fa fa-trash-o'></i></a>
                                    </center></td>
                                 </tr>";
 
                            $no++;
                        }
                    ?>
 
 
 
                    </tbody>
                    </table>
                </div>
            </div>
            </div>
            <!-- /Basic Data Tables Example --> 
 
<?php 
    if (isset($_GET[delete])){
        mysql_query("DELETE FROM data_karyawan where nik='$_GET[delete]'");
        echo "<script>document.location='kegiatan.mu';</script>";
    }
?>
 
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//Atas perhatian dan kerjasamanya saya ucapkan terima kasih