EDD SL License Key Structure

sl-key.php

<?php // DO NOT COPY THIS LINE

// SL license key structure based on username, time purchased, md5
function sd_edd_license_usernam_date_md5( $key, $license_id, $download_id, $payment_id, $cart_index ) {

	$name      = get_user_by( 'email', edd_get_payment_user_email( $payment_id ) );
	$date      = get_post_field( 'post_date', $payment_id );
	$timestamp = strtotime($date);
	$nice_date = date( 'Yndhis', $timestamp );
	$license   = md5( $license_id );
	$key       = $name->user_nicename . '_' . $nice_date . '_' . $license;

	return $key;
}
add_filter( 'edd_sl_generate_license_key', 'sd_edd_license_usernam_date_md5', 10, 5 );