Looking for to do scheduling app

Hi all,

I'm looking for some advice!

I'm looking for a very special kind of to do app, it's like a cross between a to do and a calendar app!

I want to be able to schedule certain work in during my day, for example - i may be working on a long term project and want to work on it from 9 am until 12pm, when i then want to schedule lunch then from 1pm until 2pm i want to work on a different project. So rather than a to do list with deadlines, just a scheduling thing? Does that make sense?!

I am using iCal at the moment, but although I love the app it becomes very cluttered with this approach, I have tried several to do apps and they only allow due dates. Any advice would be mucho appreciated.

Thanks in advance