Hi, I'm not sure if I entirely understand your objective, but if I do, how about
Completeddatetime ON OR AFTER Startoggledatetime + 0.75
(I don't have access to a computer today for checking so there may be syntax errors, sorry)
You should adjust the 0.75 to match your lifestyle. What this says is that if you complete a task within 18 hours (24 x 0.75) after starring it, it's normal, if it takes longer it goes on to the list. Side benefit: if you star something at noon and complete it at 1 am, it will count as "same day" because it's less than 18 hours
Let know if this is not what you wanted
-Dwight