Service Method switch - with time frame

The scenario is we would like to ship Orders with the 'DPD 24' Service if ordered from Friday after 3pm till Thursday at 2pm, every week. However on Friday (order placed after 2pm Thursday, will go the next day) only we would like to ship items on the 'Royal Mail 24 Tracked' service from. As with DPD Saturday delivery is very expensive however Royal Mail is a lot cheaper and they do actually deliver on Saturday's, is this possible to switch method on certain days/time?

Thanks, Sam