This visualization displays temporal database relationships from Snodgrass’s SQL model, using rectangles to map validity and registration intervals on dual time axes. D3 v7’s `scaleTime`, `axisLeft`, and `axisBottom` render the SVG graph, while custom tooltip handlers on mouse events reveal date details. The code derives adjusted end dates for open intervals and computes rectangle widths and heights from the scale domains. Data originates from static JavaScript arrays with ISO date strings, parsed into `Date` objects for plotting.