You are required to ship to the buyer within 7 days from the date of order, and must be able to provide proof of delivery.
At the same time, you'll also have to make sure that the purchased item reaches the buyer within 14 days from the date of order.
If no proof of delivery (indicating item has been shipped within 7 days of order date) can be provided or if the item does not reach the buyer within 14 days, the buyer can request for a refund of purchase.