What if more hot water is required, i.e. additional people coming to stay?
There are a few options here:
You could put the cylinder onto manual mode, which will result in it working the same way a standard electric hot water cylinder (there will be no savings during this time period) and then revert back to your preferred setting once your guests have left.
Alternatively, if you still want to enjoy some savings then you can increase the level of comfort on the controller, which means that the cylinder will produce more hot water while still delivering savings.