AutomateWoo - Action function to change subscription next payment date

file.php

<?php
/**
 * AutomateWoo action function to extend a subscription by 3 months.
 *
 * A note will be added to the subscription.
 *
 * Ensures that the dates near the end of the month are logically handled and do not shift to the start of the following month.
 * 
 * Custom action function docs: https://automatewoo.com/docs/actions/custom-functions/
 *
 * @param $workflow AutomateWoo\Workflow
 */
function my_extend_subscription_automatewoo_action( $workflow ) {
	// Valid options are: day, week, month or year
	$date_period = 'month';
	// E.g. extend by 3 months.
	$number_of_periods = 3;

	$subscription = $workflow->data_layer()->get_subscription();
	$payment_date = $subscription->get_date( 'next_payment' );

	if ( ! $payment_date ) {
		return;
	}

	$payment_date_timestamp = wcs_date_to_time( $payment_date );
	$new_payment_date_timestamp = wcs_add_time( $number_of_periods, $date_period, $payment_date_timestamp );

	// Update the next payment date
	$subscription->update_dates(
		array(
			'next_payment' => gmdate( 'Y-m-d H:i:s', $new_payment_date_timestamp ),
		)
	);

	// Add note to subscription
	$subscription->add_order_note(
		sprintf(
			'Subscription next payment date was extended from %s to %s by workflow: %s',
			gmdate( wc_date_format(), $payment_date_timestamp ),
			gmdate( wc_date_format(), $new_payment_date_timestamp ),
			$workflow->get_title()
		)
	);
}

Hi Dan, I don't get how you can moodify your snippet to move the 'next_payment' day to the first day of each month...
Thank's