[AutomateWoo] Custom date variable for meta field. More info at https://automatewoo.com/docs/variables/custom-variables/

functions.php

<?php

add_filter( 'automatewoo/variables', 'my_automatewoo_variables' );

/**
 * @param $variables array
 * @return array
 */
function my_automatewoo_variables( $variables ) {
	$variables['order']['my_custom_date'] = dirname(__FILE__) . '/variable-my-custom-date.php';
	return $variables;
}

variable-my-custom-date.php

<?php

if ( ! defined( 'ABSPATH' ) ) exit;

/**
 * @class My_AW_Variable_Custom_Date
 */
class My_AW_Variable_Custom_Date extends AutomateWoo\Variable_Abstract_Datetime {

	protected $name = 'order.custom_date';

	
	function load_admin_details() {
		$this->description = __( '...', 'automatewoo');
		parent::load_admin_details();
	}


	/**
	 * @param $order WC_Order
	 * @param $parameters array
	 * @return string|false
	 */
	function get_value( $order, $parameters ) {
		$timestamp = $order->get_meta( '_my_custom_timestamp' );
		if ( ! $timestamp ) {
			return false;
		}

		$date = new DateTime();
		$date->setTimestamp( $timestamp );

		return $this->format_datetime( $date, $parameters );
	}
}

return new My_AW_Variable_Custom_Date();