WordPress at a glance
filter is not described

post_password_expires filter-hook . WP 3.7.0

Filters the life span of the post password cookie.

By default, the cookie expires 10 days from creation. To turn this into a session cookie, return 0.

Usage

add_filter( 'post_password_expires', 'filter_function_name_2400' );
function filter_function_name_2400( $expires ){
	// filter...

	return $expires;
}
$expires(int)
The expiry time, as passed to setcookie().

Where the hook is called

In file: /wp-login.php
post_password_expires
wp-login.php 491
$expire = apply_filters( 'post_password_expires', time() + 10 * DAY_IN_SECONDS );

Where the hook is used (in WP core)

Does not used.