Show HN: How to Mentally Calculate the Day of the Week for Any Date

Cool site! When I do this trick I prefer using Bob Goddard's 'first Sunday' method [0]. It minimises the number of operations you need to do and makes it so you only need to keep track of one running total.

[0] https://firstsundaydoomsday.blogspot.com/2009/12/quick-start...

It's pretty bad form to give the doomsday algorithm and not give credit to John H. Conway who invented it. https://en.wikipedia.org/wiki/Doomsday_rule