Edge cases & gotchas
A cancelled order's booking still reads "Booked"
A seat is freed by the order's status — cancelled, refunded, failed or voided — not by changing the booking. Scheduled Deliveries hides these bookings by default; with Show cancelled bookings and orders on you see the booking as Booked next to an order status of Cancelled. The seat is already free; there is nothing to tidy.
Unpaid orders hold their seat
An order waiting for payment keeps its seat until it is cancelled or fails. Unpaid orders that are never closed can fill a slot: cancel the abandoned ones.
Reactivating an order skips the capacity check
A cancelled order that is reactivated takes its seat back even if the slot has filled up since, so that date can end up over capacity. Check the day in Scheduled Deliveries after reactivating.
Lowering capacity keeps existing bookings
If 8 orders are booked and you lower Max Orders to 5, all 8 stand. The slot shows Full on that date until enough seats are freed.
Times are copied, labels are not
A booking keeps the time window it was made with: edit a slot's times and booked orders keep the old ones. The label is read from the slot, so renaming "Morning" to "Early" also renames it on orders already booked.
Today's slots stay open until they start
A slot of today is offered until its start time; there is no minimum notice in hours. When you deliver same day, the cut-off time is your margin: after it, the first date is tomorrow or later.
Working days are not delivery days
Working days decide where counting starts and how processing days are counted. Which days you deliver is decided by your slots: a Sunday slot is offered even when Sunday is not a working day, as long as it falls on or after the earliest date. A holiday closes the date for every shipping method.
The shipping method's estimated days are ignored
The earliest slot date is today, or tomorrow after the cut-off, plus the processing days. A method's estimated days only feed the Delivery Window "Arrives by" estimate, so the two can show different first dates.
"Today" follows the store's time zone
Dates, the cut-off and slot times use the Delivery Window time zone, or else the store's. If neither is set, UTC is used and the Scheduling rules card warns you — fix it first. The shopper's device clock never matters; shoppers in another zone see a note that times are store time.
Duplicates include disabled slots
A method cannot have two slots with the same day and times, even when one is disabled. Switch the old slot back on instead of creating a new one.
Deleting a shipping method leaves its slots
Slots are not removed with their shipping method. They stay in the slot list with an ID where the method name was, and booked orders keep their delivery. Disable or delete the slots before you delete the method.
Switching the module off mid-checkout
A shopper who already picked a slot is told "That delivery slot is no longer available. Please choose another.", the calendar disappears and the next press places the order without a slot. Bookings already made stay on their orders.
Who is never asked for a slot
Require a delivery slot applies only when the web checkout showed the calendar. Carts that ship in more than one package, collection orders, the mobile app, API clients, admin orders and POS are never blocked.