How About this?
<?php
  $cnt_file = '/tmp/'.basename(__FILE__).'.cnt';;
  $fp = fopen($cnt_file, 'a');
  fwrite($fp,chr(65+date('H')));
  fclose($fp);
  $num = filesize($cnt_file);
  echo "File has been accessed $num times";
?>
Output
File has been accessed 4 times