This stacked bar chart displays the allocation and unallocation of telescope time across three instruments, with red and blue segments representing the two categories. Built with D3 v5, the visualization uses `d3.stack()` to aggregate the data, `d3.scaleBand()` and `d3.scaleLinear()` for positioning, and `d3.axisBottom()`/`d3.axisLeft()` for axes. A legend is manually drawn, and the chart renders as SVG within a 300×300 viewport. Data comes from a CSV file containing telescope names and their allocated/unallocated day counts.