Startup Idea : Task list with blocks of time.

There are many Task to do list that allow task to be categorized and scheduled, but they are just a long list. I want to be able to drop similar task into a block of time, so I can divide the day into blocks of similar task. For instance I would like work on long written tasks from 9-12, and make calls from 1-3 and short written task from 3-5 pm. As I enter a task I want to categorize it and depending on its category it would be inserted into a time block. If the task was not completed I could manually move it to a specific block of time, or it would automatically move to the next bloc of set aside for that task. Within the task block I should be able to move task up and down into the order I want to tackle that particular task list. Task need to be able to be dragged and dropped from day to day and moved into a specific order of completion within the block of time.