Where can a seller manage their weekend delivery times for their Amazon.com products?

In their Seller Central account is the correct answer because sellers can manage their weekend delivery times through the settings available in their Seller Central account. In Seller Central, sellers have access to various shipping and fulfillment settings, including options to adjust delivery times, set handling times, and specify when they can deliver orders, such as during weekends. This helps ensure that the shipping options reflect the seller's operational capabilities and meet customer expectations for delivery. The other options, such as Seller University and within the product listing, are not directly related to managing specific delivery times.