Scheduling the Duration of a Layout

I'm fairly new to Xibo and particularly to scheduling multiple layouts to run on one display at a time. From documentation and other answers on this forum, am I to understand that Xibo is smart and will run a layout until all content has played through at least once (no matter what duration that takes) before looping to the next layout that is scheduled concurrently? Or, do I need to calculate the duration of each layout and then set that duration on the layout somehow - or on the schedule - to tell Xibo how long to display each layout before looping to the next one?

Thanks from a Xibo newbie!