Miscellaneous calendar converters

I like making silly calendar converters. It's fun! Here's a list of all the ones I've made and put online, ranked roughly from most to least useful. Links marked with a star are based on "Calendrical Calculations: The Ultimate Edition" by Edward M. Reingold and Nachum Dershowitz and the JavaScript library "calendrica-js" by Sarabveer Singh based on the aforementioned book.