BB pal Russell Walks created this wonderful Gallifreyan Perpetual Calendar and Galactic Star Chart for Timelords and their fans. It enables you to "find the day of the week for any date between 1600 and 9999 AD." Large prints are $30.
David Pescovitz is Boing Boing's co-editor/managing partner. He's also a research director at Institute for the Future. On Instagram, he's @pesco.