With Marvin's do dates you can schedule tasks to a specific day. This means you want to do this task on that day.
There is a separate list for each day. You can navigate to each day with the arrow keys or the calendar in the sidebar.
Each day Marvin automatically makes "Today" the new default view. So you are always looking at the current day list.
This means that if you did not complete a task that was scheduled to a previous day, they are now easy to forget about.
Instead of rescheduling everything automatically to the new day, Marvin collects all left behind tasks in the reschedule dialog so you can deal with them appropriately.
Clicking on the reschedule button shows you a list of all tasks that are scheduled to a day in the past.
You can click on the checkbox to complete them if you forgot to check them off.
You can also select all of them with the "select all" at the top or by pressing cmd+a on your keyboard.
Bulk selection works as well here. Use the shift key to select the start and end of a selection, or use the cmd key to pick single tasks.
You can bring up this dialog with the shortcut "r" (for rescheduling).
You can also select all your tasks in the dialog with cmd+a
Or pick which tasks you want to select by holding down cmd and clicking on them.
Hold down shift and click the first and last task to make a selection field.
By using this strategy you can have all unfinished tasks automatically moved to today.
In the settings of this strategy you can choose at which time you'd like tasks to roll over, and also if you want recurring tasks to be rolled over as well.