set_cache_duration()

class SimplePie {
	set_cache_duration ( [int $seconds = 3600] )
}

Set the minimum time (in seconds) for which a feed will be cached.

• Available since SimplePie 1.0.
• Previously existed as cache_max_minutes() since SimplePie Preview Release.

The number of seconds to cache for. 60 is 1 minute, 600 is 10 minutes, 900 is 15 minutes, 1800 is 30 minutes.

$feed = new SimplePie();
$feed->set_feed_url('http://simplepie.org/blog/feed/');
$feed->set_cache_duration(1800);
$feed->init();
$feed->handle_content_type();
echo $feed->get_title();