Right on their home page:
Free Shipping
Receive free standard shipping on your entire purchase from 11/25/2021 from 9:01pm ET thru 11/29/2021 11:59pm (ET). Each item ordered requiring air shipment will be charged an additional fee. Offer pertains to purchases initiated on HSN.com or via HSNtv only. TV and online orders cannot be combined. All items must be purchased on the same day. We authorize the total amount for each item, including applicable shipping and handling charges and tax, on your credit or debit card as you shop today before any order value discounts are applied. The available funds for spending with the card will be subject to a hold equal to this authorized total amount. The amount we ultimately charge your credit or debit card will reflect applicable discounts but, please note that, depending on your bank or financial institution, it may take up to 30 days for the authorized hold amount and charged amount to be reconciled on your card. If using a debit card for your purchase, please plan accordingly. HSN reserves the right to change or terminate this offer at any time.