Couldnt figure out how to achieve the formatting straight in mysql so made this quite lame script. Add your loop. I dont know where the dates are fetched so I didnt add any loop but you get the idea.
$date='22/04/03'; // DD/MM/YY
$d=explode('/',$date);
// my poor Y2K-fix :) Assuming you dont have dates before 1970 and over 2070 :D
if ($d[2]>70 && $d[2]<100)
$c=19;
else
$c=20;
$timestamp=$c.$d[2].$d[1].$d[0].'000000';
echo $timestamp; // prints 20030422000000 so it is in right format to insert to database timestamp(14).