gistfile1.php

<?php

class AncientFileFilter extends \FilterIterator {

	protected $DaysOld = 7;

	public function __construct($dir,$days=null) {

		// is the specified directory valid?
		if(!is_string($dir) || !is_dir($dir) || !is_readable($dir))
		throw new Exception("This '{$dir}' is not valid or readable.");

		// construct with an inner filesystem iterator.
		parent::__construct(new \FilesystemIterator($dir));

		// how old is old in this day of age?
		if(is_int($days) || is_float($days))
		$this->DaysOld = $days;

		return;
	}

	public function accept() {
		$file = $this->current();

		// list the file as ancient if it has been stale for more than
		// x days.
		if($file->getMTime() <= (time()-(86400*$this->DaysOld)))
		return true;

		// else do not list the file.
		else return false;
	}
}

// delete files more than 30 days stale.
$diter = new AncientFileFilter('/some/directory', 30);
iterator_apply($diter, 'unlink', $diter->current()->getPathname());