Show HN: How to mentally calculate the day of the week for any date
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Re: Show HN: How to mentally calculate the day of the week for any date
#2It'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
Re: Show HN: How to mentally calculate the day of the week for any date
#3It'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
He’s well credited in the article…
Re: Show HN: How to mentally calculate the day of the week for any date
#4It'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
He’s well credited in the article…
Pretty sure he was not when I posted my comment. It currently says "more on him at the end" and that bit seems not to have been written yet. Also there are two mathematicians called "John Conway" so it's good form to say "John H Conway".
Re: Show HN: How to mentally calculate the day of the week for any date
#5Earlier quoted context omitted.
He’s well credited in the article…
Pretty sure he was not when I posted my comment. It currently says "more on him at the end" and that bit seems not to have been written yet. Also there are two mathematicians called "John Conway" so it's good form to say "John H Conway".
Author here, good call! I credit Conway in the center of the article, the content for "more on him at the end" was hidden after reader finish the challenge in part 6. I guess it worth to show it by default, updated already.
I'd also need to thanks for Dr. Arthur Benjamin. I saw his "That math show" with my 9 years old where he introduced this Doomsday rule, I thought it was really cool and try to create some interactive tutorial for it. Would love to see if this can help other kids or adults https://www.thatmathshow.com/
Re: Show HN: How to mentally calculate the day of the week for any date
#6Cool 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...
Re: Show HN: How to mentally calculate the day of the week for any date
#7It'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
he did
Re: Show HN: How to mentally calculate the day of the week for any date
#8V. Cool - thank you for building and sharing
Re: Show HN: How to mentally calculate the day of the week for any date
#9This is amazing! What a cool website.
Re: Show HN: How to mentally calculate the day of the week for any date
#10[flagged]