What the terms say
The terms say a bank holiday on Friday or Monday moves the delivery to the next working day after that. Internet orders received by 3pm aim to be delivered by 5.30pm the next working day. If that next day is a bank holiday, the aim moves.
Weekends are not dispatch days. A bank holiday is not turned into a dispatch day by placing the order early.
The cutoff on the working day before
On the last working day before the holiday, 3pm is still the cutoff for that day’s dispatch. An order at 3.01pm waits for the next dispatch day.
The 1 to 3 day courier description on the homepage still applies, depending on the items in the order.