Yes you can, but only for the following categories: Balloons, Inflatables, Tanks & Pumps, and all Food & Drinks.
Based on the shipping policies set by the vendor, you will be able to choose from different dates and time slots on the shopping cart page.
Click on "Choose Date & Time".
You will then see a selection of different dates and time slots (each is a three-hour block). Pick one, and allow 30 seconds for your shopping cart to refresh.
After it refreshes, your selected delivery/pick up date and time will be shown next to the product. If you wish to edit it, click on the Pen icon. Do ensure it is correct before you pay because you cannot amend your order after that.
If there is no option to pick a time slot, the product will be delivered within the range of dates specified next to the product.