they're not included, but employment contracts tend to be written as X days off + all bank/public holidays (as employers generally close their offices on bank/public holidays)
the guarantee of 5.6 weeks paid holiday doesn't guarantee when they are taken, as long as you receive at least 5.6
I've always received 6.6 weeks, some of which my employers request I take on bank/public holidays.
the other big difference is in the UK I've never even heard of anyone even feeling remotely pressured into not taking their full entitlement (in fear of being labelled a slacker)