Abstract: A flexible layout system is disclosed herein that improves infinite scrolling capabilities and other animations in software calendars. In an implementation, a time period of a viewport in a user interface may change relative to a panel in a calendar. As the viewport changes, a mapping component informs other components of a new time period coming into view in the view port as a result of a scrolling event. The mapping component may also respond to requests from another component with layout information for the visual representation of the new time period (e.g. position and dimension). In this manner, the responsibility for determining layout information is encapsulated.