Ricky
There's an old true-ism, "work expands to fill the time".
If you can do it all Monday to Friday 9 till 5 then you will do so. Obviously there will be the exception that proves the rule.
But to illustrate the point...I never have my phone turned on during a Sunday (and rarely on a Saturday). But do you know what? There are very few messages left for me, or even calls where somebody doesn't leave a message during the weekend. Of those who do phone, many leave a message to the effect of " I know this is the weekend, please phone me back when you get this message during the working week."
Obviously my experiences will not be reflected across the great and the good cc fraternity but nevertheless it is a valid expression of experience.
The moral of all this pontificating......
If you don't want to work on a Bank Holiday then don't. You will inevitably find you do as much work as you can handle and not lose out on any by sticking to your principles.