You can calculate the weekday of any given date mentally within 10 seconds like a genius even if you are not.

You just need to learn about the Doomsday algorithm devised by a mathematician John Conway in 1973, and practice it to speed up your mental calculation.

This app will provide you the specific method for calculating the weekday, step by step tutorial, and random exercise.

In the main page, you can type any date and check which weekday is it. And in the step by step tutorial page, you can see the exact process how it calculates with detailed examples. I put almost everything that can help your calculation faster in that page.

You can generate random date and practice your skill in the random exercise page. The more you practice, The faster your mental calculation will be.

Conway can now usually give a correct answer in under two seconds. Will you?