This is the dirtiest component of going between DOM and the event abstraction (start and end times). When someone resizes the event or moves it, it's going to take some kind of pixel calculations at one point or another, even if they're very generalized, since they used their mouse to do that. This is the point at which I decided to deal with that. Otherwise the events are all handled abstractly. The data isn't necessarily coupled with the presentation, but for example the way they move the event around on the DOM when they're dragging and dropping (presentation) has to be translated into data at one point or another (and so the function is called dom2time--translating presentation to data :).