The estimated delivery date shown on your listings is based on the time it takes you to pack and post items (your handling time), and the postage or courier services you offer.
If you can guarantee to get your items to a customer's door within four days, consider offering eBay Guaranteed Delivery.
Weekend and public holiday deliveries
Weekends and public holidays aren't included in estimated delivery dates, even though some carriers deliver on Saturdays.
A buyer may contact you if they specifically need a weekend delivery, or want a faster postage option. If they're happy to pay any difference in cost, it's up to you whether to accept their request.
Express postage on eBay
To appeal to buyers who need items quickly, consider adding express postage services, such as overnight, next-day or same-day delivery to your listing.
To offer express postage, simply go to the Add postage details section when creating a listing, and choose your preferred carrier(s) from the Services dropdown menu.