Can't find opening info on their website. I'm trying to establish if they are open on a Saturday so if I place an order tonight, it will be processed tomorrow, despatched on Wednesday and delivered on Thursday, using their 24hr service.
Normal deliveries should resume on Wednesday so ordering today and paying for 24hr should get you the order for Thursday without any problems.
Iirc the online part of the business is Monday to Friday but with a bit of luck it would be processed/dispatched on weds, but bearing in mind they will have a monstrous amount of orders to process when they get in on weds morning I wouldn't bet my house on that haopening..
FWIW when ive ordered stuff of Merlin over a BH weekend, I have often been surprised to find that it has arrived the day after the BH. This would suggest that they have staff in despatching on the BH.