The purpose of this application is to organize to-do items. This items are called tasks. A task has a few attributes to remind you what this to-do item is about.
You may set a due date to some date in the future, you will see this date in the task list in the inbox or context. When this date is reached or in the past, the task will appear first in the list and the application will display this date in red.
You may have a task which you want to start working on only after a certain date; this is the start date. When this date is reached, the application will change the status of the task from Someday to Next action and will display a notification. To make this work, set the status of your task to Someday and set a start date to some date in the future.
A task may have sub tasks. As soon as you add a sub task, the parent task will become a project task, which is visible in the task list with a P.