Some years ago I tried to simplify the Doomsday algorithm here: https://gcanyon.wordpress.com/2013/04/09/a-better-way-to-cal...

I don't think that's simpler than the algorithm at weekle, but in case anyone is curious.

How is it easier? I can do Doomsday in about 5 seconds for any year AD 1800 - 2200

I don't think I'll spend the time to memorize the part for the anchor days, but the observation that March 0, 4/4, 6/6, 8/8, 10/10, 12/12 all land on the same day will definitely come in handy.

There's other mnemonics too, "I work 9-5 at the 7/11" and the observation that Jan 3 (normal) and Jan 4 (leap) can be remembered as, "3 times out of 4, it's January 3rd; the 4th, it's Jan 4th"

Silly mnemonics but it's something. The design about even number days all landing on March 0 / last day of Feb is a good and simple one. I don't know what Weekle is innovating -- instead of using an established system of mnemonics and calculations, he just presents his own table with no comments. Maybe his inspiration was to say, "hey guys, I made my own date calculation system" to impress people who don't know about Doomsday?

As I noted in this HN post, I did not invent this system (there are other tutorials online). I'll update the web app itself to state this clearly.

The goal of the web app is more about the practice modes and daily game, people are free to use Doomsday for these if they like.