Some tasks don't have a specific time, but happen anytime during the day or even take all day. Others aren't about a specific action that needs to be done, but just remind you about an upcoming birthday.
For these tasks, so-called All-Day Tasks, Structured reserves a special place at the top of the timeline.
Create all-day tasks
Creating an all-day task is easy. Just tap the ➕ to create a normal task. Then tap the More… button next to the When?. This will bring up a popup menu, where you can select Change to All-Day.
Now you've set your task to appear in this top space. You can change the day, by tapping the All-Day on ... button, or add a specific time again by tapping Add Time.
Completing an all-day task
All-Day tasks can also be completed. To complete an all-day task, you can either just long-press it or tap it to bring up the detail dialog and then hit Complete.
Completed all-day tasks have their color filled in, and their title crossed off.