Want to know why the date bar is showing up on your highlights page? Simple.
It is because you have your itinerary items also showing on your highlights. If you have part of your itinerary showing on your highlights, the date bar will automatically show up.
In order to remove the date bar from your Trip Page, just remove the itinerary items from also showing as highlights. You do that by editing the itinerary item and making sure the 'Also show on highlights' is unchecked.