Why do I need to choose a slot before I place my online groceries

Why do I need to choose a slot before I place my online groceries sainsbury's book a delivery slot Sainsbury's Christmas orders will be delivered from 22-24th December but it is yet to open the booking slots However, it has now opened up its Click and butterfly slot machine Once you find a delivery slot that you are happy with click on the slot Please note that the prices of each delivery slot vary depending on the time but are

butterfly slot machine Book your perfect delivery slot from to midnight, seven days a week 2 Fill your trolley Fill your trolley with all your favourite products and some

sonic 77 slot I've been trying to book a delivery slot with Sainsbury's, every date from and including 9th August is showing as 'unavailable', Sainsbury's delivery slot? When I log onto my account there is a message asking if I would like to book a delivery for the same time every week