Option for not cutting the ends of graph

The graph editing feature marks the areas as awake only in the middle, but if I press the scissors on a selection at the end or the beginning, it deletes the selection. I would like to keep the part I select so that I can keep track of what time I went to bed and how long it took me to fall asleep, and occasionally what time I woke up and how long I stayed in bed trying to get back to sleep before giving up for the day.
(suggestion from support email by Mortimer)