When you start your revision, normally you start with what you like. You shouldn’t start with what you like or what you don’t like but you should prioritize your revision with chapters which are important. For details on priority, refer priority.
You have numerous books to revise while you start those 20 hours of preparation between 2 exams. You should plan your revision with sheer clarity- what chapters you are going to study, which books you will refer for each chapter, etc. The best solution we found to this problem was reading only 1 book for Direct Taxes instead of going through Direct tax summary book, examples book, select case book. You can check out the sample of Direct Tax Notes.