Find the file from 15 days ago

How can I get difference date between today and 15 days ago and all filename is was created before 15 days ago?

It has to be korn shell script.

Thanks.

#!/bin/ksh

cd /PATH/to/files
touch somefile
ls -rt *.log | tail -1 | read newfile
touch_value=$(perl -e '
	$mtime=(stat $ARGV[0])[9];
	$mtime = $mtime - (86400*15);
	($sec,$min,$hour,$mday,$mon,$year,$wday,
					 $yday,$isdst)
					   = localtime($mtime);
	 printf "%d%02d%02d%02d%02d\n", $year+1900, $month+1, $day+1, $hour, $min;
			 ' $newfile )
touch -t $touch_value touchfile
find . ! -newer touchfile -print


edit - mistake - used a file not today's date

The creation time of files is not stored on *nix systems. You can use the time the file was last modified:

find . -mtime +15 -print