The fact that this is a perpetual calendar is actually secondary to the incredible amount of detail and information contained within the design. Artist Russell Walks created this “Gallifreyan Perpetual Calendar and Galactic Star Chart” and filled it with images and quotes from the series. It will let you find the day of the week for any date between 1600 and 9999 AD all set on a backdrop of the night sky on November 23, 1963, the day the series first aired. This officially licensed product measures 24″ x 36″ and will begin shipping on March 15th. If you’re in the US, order before February 15th and shipping is free!