Doomsday Calculator, Doomsday Day Of The Week Clock, John Conway, Doomsday Calendar, Bar Game, Math Gift, Doomsday Device, Find The Date

Use this device to quickly find the day of the week for any date between 1901 and 2099. Doomsday in this context does not refer to world catastrophe, but rather to particular dates in any given year which always fall on the same day. That day is called the ?Doomsday? for that given year. John Conway, UK mathematician, in 1973 developed a technique where a bright person with a little practice can within seconds determine the day of the week for any given date. You can read more about this by doing a search on ?Doomsday day of the week ? on internet or Youtube. It?s a fascinating topic.This device takes those math concepts and converts them to a physical device that anyone can use. I found the basis for this at Jerry Slocum?s puzzle museum where a paper model exists credited to John Foshee. As I love math that can be converted to physical objects I fell in love with it and immediately began constructing one. The complete instructions on how to use it are lasered on the back, so you don?t have to work about losing the instructions.Made here in our Hudson, FL woodshop.CreativeCrafthouse.comInstructionsFor Years 1901-1999:1. Locate the last 2 digits of the year on the large outer disk2. Rotate the inner disk so that the MONTH is directly below the YEAR Years in brackets (XX) are leap years. For these, use (Jan) and Feb) in place of Jan and Feb.3. Day of the week is next to the date of the month on the inner disk.For years 2000-2099:Follow the steps above, then back up ONE DAY. For exDec 7, 1941 = SUN so Dec 7, 2041 = SATThis is because the calculator uses the ?Anchor Date? for the 20st century which is a Weds while the Anchor Date for the 21st century is a Tuesday. Thus backing off a day makes everything align.To view a video on this item, cut and paste this link:https://studio.youtube.com/video/ccp5fMp7gpk/edit