How to set Next Payment date in Woocommerce Subscriptions?

Question

I would like to change the next payment date of active subscriptions after the Initial (first) order was created.

current code which does not work. Why? What am i missing?

//fires when new order payment is complete (NOT RENEWAL but original order!)
add_action('woocommerce_payment_complete', 'fm_upate_next_payment_datetime');

function fm_upate_next_payment_datetime ( $order_id ) {

if (WC_Subscriptions_Order::order_contains_subscription( $order_id ) == false) return;      
$subscription_key = WC_Subscriptions_Manager::get_subscription_key( $order_id, $product_id
= '');

 //hard code next payment date...(must be in future)
$next_payment = date( 'Y-m-d H:i:s', '2016-05-20 00:10:10' );

//set the new payment date  
WC_Subscriptions_Manager::set_next_payment_date( $subscription_key, $user_id = '', $next_payment );

}

Answer 1

what you said and also we need to set a start date! (can be NOW) but if its not passed it will throw an error. Got it to work like this:

function saveNewDate($post_id) {

    $subscription = wcs_get_subscription( $post_id );
    $dates        = array();

    $datetime           = current_time( 'timestamp', true );
    $dates[ 'start' ] = date( 'Y-m-d H:i:s', $datetime );
    $datetime = strtotime( "08/23/2016 23:30" );
    $dates['next_payment'] = date( 'Y-m-d H:i:s', $datetime );

    try {
        $subscription->update_dates( $dates, 'gmt' );
        wp_cache_delete( $post_id, 'posts' );
    } catch ( Exception $e ) {
        wcs_add_admin_notice( $e->getMessage(), 'error' );
    }
}

Answer 2

working solution for me is (see also https://docs.woocommerce.com/document/subscriptions/develop/functions/#section-4):

function update_next_payment_date($subscription) {
    $date = new DateTime('2021-05-28');
    $date->setTime(8, 55);

    $subscription_next_payment_date = date_format($date, 'Y-m-d H:i:s'); // = '2021-05-28 08:55:00'

    $new_dates = array(
        'start' => $subscription->get_date('start'),
        'trial_end' => $subscription->get_date('trial_end'),
        'next_payment' => $subscription_next_payment_date,
        'last_payment' => $subscription->get_date('last_payment'),
        'end' => $subscription->get_date('end'),
    );

    $subscription->update_dates($new_dates);
}