<?php
#utc
#echo date(DATE_RFC822);

list($us, $unix_time) = explode(' ', microtime());
#die( pow(10,6) * $us.'-'.$unix_time );

$seq = pow(10,6) * $us % 1000;
$dict= range('a', 'z');
for ($i = 0; $i < 9; $i++){
  $k = array_rand($dict);
  $seq.= $dict[$k];
}

echo $unix_time.'-'.$seq;