I go to Colfe's school, which is in Lee South East London, and have also worked at the Kent College and Baston School camps.
The way i see it is that you spent the first hour or so of the day with the parents, signing the kids into camp, and then you do a bit of admin, then spend time with the kids untill lunch, where you will have a break, then the afternoon with the kids, unless the Camp Director wants you to do something specific (there are a few 'whole camp' games like the olympics, wide game ect.) so you might help get those organised, other than that you spend about an hour in the evening signing out the children!
Thats basically an average day! Hope that answers your question!! X