It guesses the day of the week with an algorithm that I created on my own. DISCLAIMER --------------------------------------------------------- I know the calculator refuses to work for years <1900 and >2100 but it still works between those dates and when I get time, I will attempt to fix it.
This took around 10 hours of bug fixing and design flaws so leave a comment if you find a bug. All calculations are based off of my intuitive understanding of how days of the week changes each year and the apple calendar. --------------------------------------------------------------------------------- v1.0 - Release