Discount a Paid Memberships Pro level half way through the year.

pmpro_checkout_level.php

<?php
/*
	Add this code into a custom plugin. Combine this with the pmpro-set-expiration-date and/or pmpro-subscription-delay plugins
	to have memberships expire/renew on the same date, e.g. Y2-01-01 to expire/renew on Jan 1 next year.
	
	You can update the logic to check for different months or adjust the price in a different way. The code below divides the
	initial payment by 2 July 1 through Dec 31.
*/
function pmpro_checkout_level_half_off_mid_year($level) {
	$month = date('n', current_time('timestamp');
	if($month > 6) {
		//July or later
		if($level->initial_payment > 0)
			$level->initial_payment = number_format($level->initial_payment/2, 2);
	}

	return $level;
}
add_filter('pmpro_checkout_level', 'pmpro_checkout_level_half_off_mid_year');

There is an error on line 10. We can't edit these gists under the strangerstudios user anymore. You can find the updated/fixed gist here: https://gist.github.com/kimcoleman/4d494574fe9a64285ab94effd6ccf3d9