The priceValidUntil property is only shown in WooCommerce when a sale has been scheduled. This means a value must be given for both "Sale price", and the Sale price "from" and "to" dates.


 

If a product is not on sale, there's no way to get the end date value to satisfy the priceValidUntil property. Since Google's Product Feature Guidelines state that this is only a recommended property, missing this information will not impact eligibility for rich results in search.