When user renews membership we append the duration to their current enddate

pmpro-append-to-end.php

<?php
/*
Plugin Name: Paid Memberships Pro: Extend membership by new level duration
Plugin URI: http://www.paidmembershipspro.com/wp/pmpro-customizations/
Description: On change of level, modify the end date to add the new level's time
Version: 1.0
Requires: 4.5.3
Author: Thomas Sjolshagen <[email protected]>
Author URI: http://www.eighty20results.com/thomas-sjolshagen/
License: GPL2
License URI: https://www.gnu.org/licenses/gpl-2.0.html
*/

function e20r_extend_enddate_by_duration( $enddate, $user_id, $level, $startdate ) {

	// If the user has a current membership level
	if ( false !== ( $current_level = pmpro_getMembershipLevelForUser( $user_id ) )
	     && ! empty( $level->expiration_number ) && ! empty( $level->expiration_period )
	) {

		$enddate = date( 'Y-m-d', strtotime( "+ {$level->expiration_number} {$level->expiration_period}", $current_level->enddate ) );
	}

	return $enddate;
}

add_filter( 'pmpro_checkout_end_date', 'e20r_extend_enddate_by_duration', 10, 4 );

How to apply this to my site?
Please let me know

Copy the gist to a .php file that you place in a wp-content/plugins/e20r-extend-enddate directory on your web server. Then activate the new plugin on the Plugins page of your WordPress site.

Hi!
I'm trying to use this but it dosn't work :( When I buy any subscription it will calculated days from today, not from end date. What can I do?

The outcome is going to depend a bit on how the membership level is defined (i.e. is it a recurring membership with the expiration period configured). If the membership level is not a recurring membership level then this gist won't do anything. Another possibility is that the filter name changed in PMPro proper (not sure if that could have happened as I haven't needed to check for a while)