PMPro Customizations to allow non-members to view restricted posts if they are less than 30 days old.

open_new_posts_to_non_members.php

/*
	Allow non-members to view restricted posts if they are less than 30 days old.

	Add this code to a custom plugin.

	Change the '-30 Days' below if you'd like to allow access for longer or shorter.
*/
function open_new_posts_to_non_members($hasaccess, $thepost, $theuser, $post_membership_levels)
{
	global $wpdb;
	
	//if PMPro says true already, return true
	if($hasaccess)
		return $hasaccess;	

	//figure out dates to check
	$cutoff = strtotime( '-30 Days', current_time( 'timestamp' ) );
	$published = strtotime( $thepost->post_date, current_time('timestamp') );
	
	//if published after the cuttoff, then allow access for now
	if($published > $cutoff)
		$hasaccess = true;
	
	return $hasaccess;
}
add_filter("pmpro_has_membership_access_filter", "open_new_posts_to_non_members", 10, 4);

This recipe is included in the blog post on "Lock or Unlock Posts Based on Age and Post Date" at Paid Memberships Pro here: https://www.paidmembershipspro.com/lock-unlock-posts-based-age-post-date/