Well, there's a problem with your request: what does it mean for a task to be allotted for a given day? Due that day? Starts that day? Starts before that day and due after that day? Part of a project that is due that day, or starts that day, or ...?
A better solution is to choose the tasks you want summed up, and run a script to give you the total. Don't forget that adage of "garbage in, garbage out" — your total will only be as good as the individual estimates included, and you'll want to watch out for tasks which don't have an estimate!
You can find such a script at
http://forums.omnigroup.com/showpost...6&postcount=14 which will handle a selection of arbitrary tasks (earlier versions in the thread were aimed at summing the time needed for a given project).