WordPress at a glance
filter is not described

wp_feed_cache_transient_lifetime filter-hook . WP 2.8.0

Filters the transient lifetime of the feed cache.

Usage

add_filter( 'wp_feed_cache_transient_lifetime', 'filter_function_name_4651', 10, 2 );
function filter_function_name_4651( $lifetime, $filename ){
	// filter...

	return $lifetime;
}
$lifetime(int)
Cache duration in seconds.
Default: 43200 seconds (12 hours)
$filename(string)
Unique identifier for the cache object.

Where the hook is called

WP_Feed_Cache_Transient::__construct()
wp_feed_cache_transient_lifetime
fetch_feed()
wp_feed_cache_transient_lifetime
wp-includes/class-wp-feed-cache-transient.php 66
$this->lifetime = apply_filters( 'wp_feed_cache_transient_lifetime', $lifetime, $filename);
wp-includes/feed.php 693
$feed->set_cache_duration( apply_filters( 'wp_feed_cache_transient_lifetime', 12 * HOUR_IN_SECONDS, $url ) );

Where the hook is used (in WP core)

Does not used.