I can tell you what day of the week you were born on (without looking it up)

If you feel I've earned it you can support the channel here: / mikeboyd
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I am so grateful for any support you choose to give, financial or emotional! 🙏 This week I thought I'd learn the "doomsday" algorithm which allows you to tell what day of the week any date will fall on. Turns out it's not too difficult!
The @numberphile video I learned this from: • The Doomsday Algorithm...
My name is Mike Boyd and I make videos documenting my process of learning stuff really fast. Subscribe for more upcoming videos and feel free to tell me what you'd like me to learn next in the comments.
Instagram: / mikeboydvideo
Subscribe: / mikeboydvideo
Camera Work: Kim Boyd

[@notdarklord9227]

Plot twist: He has a 1 in 7 chance of guessing it, and he's just extremely lucky.

[@AxxLAfriku]

WOAH WOAH WOAH!!! Let me get this perfectly straight: You comment something that is completely unrelated to the fact that I have two HAZARDOUSLY HANDSOME girlfriends? Considering that I am the unprettiest KZbinr worldwide, it is really incredible. Yet you did not mention it at all. I am VERY disappointed, dear n

[@aooga9995]

@@AxxLAfriku he is back. once more AxxL appears for us

[@nite_owl_was_here]

duuuude this is such a cool trick, i was smiling like a looney on the subway

[@Bigboikilljoy]

he has dreams luck

[@DannySullivanMusic]

haha man perfect comment

[@bas2362]

Became inspired. Learnt it in 1,5 hours. Told everyone I memorized whole calendars from 1700 to 2499. Now girls can't leave me alone.

[@MCubes]

🥶

[@sauviel6296]

Sheeeeeeeeeeeesh

[@cortesdothiagofinch440]

clever

[@turtlc]

sheesh

[@radityateguh8175]

What math does to a gentleman

[@toml.3293]

Fun fact : 1700, 1800 and 1900 are not leap years, but 2000 is. Every hundred years, if the year in question can be divided by 100 and by 400 then it's a leap year (1600 and 2000 for example). Otherwise it's not. Found that by accident while training :) Thanks for the great skill Mike!!

[@Burbie]

Pretty funny u found it by accident 😂

[@memoid7777]

Every 4 is Every 100 isn't Every 400 is Every 4000 isn't Just in case someone asks you a far flung future date:)

[@ZolaniZweni]

Neil Degrasse Tyson has an of the cuff explanation about this on The Joe Rogan Experience. The Gregorian calendar was designed to accurately keep the solstice from drifting over time (like the previous Julian calendar) so those rules remove a leap-year every 100 years coz now there's too many days and add one every 400 coz now not enough and again remove a day every 1000 coz too many... All of that done by priests with a firm understanding of maths and astronomy... And some dbags still think the world is flat 😔

[@businessisboomin7252]

Damn Y'all motivate me more to start learning this trick.... should I, even tho I'm not the best at maths?

[@Burbie]

@@businessisboomin7252 u dont need to be good at math , u just need to practice this trick well

[@gamingbutnotreally6077]

Love it when people find out about the beauty of modular arithmetic

[@davidbengb8484]

What is that

[@want-diversecontent3887]

@@davidbengb8484 kzbin.info/www/bejne/onuWdHdvgpihe7M

[@freddyelhachem3772]

You should make a tier list of all the skills you have learned over the years! You could rate them on usefulness, fun and difficulty!

[@bluebaconjake405]

Oh this is an interesting video idea

[@jacobeames4093]

cool idea

[@nikmrn]

what are these replies from the bots

[@DannySullivanMusic]

that's right. 10000% right!

[@bluebaconjake405]

@@nikmrn already reported them. You should too

[@Cubeorithms]

Its crazy how helpful the Numberphile video is in learning this trick. After watching it, it took me less than an hour and now I'm getting it right almost every time! The leap years are the trickiest part.

[@90PercentNerd]

hey blue

[@applewater5642]

I love your videos Blue!

[@JoaoPauluu]

agreed, learned it the day that video was released hehehe

[@AndrewTyberg]

Yo hey blue!!

[@TheStuartstardust]

@@applewater5642 Blue as in 3 Blue one Brown?

[@merilahna]

the last day she chose on the intro is my birthday (though a thousand and 40 years in the future) which i already thought was a funny coincidence, but then he said it was a monday, which is the weekday i was born on, and so i felt like the title of the video had just been proven to me, specifically

[@copegre]

I've seen this in an old mentalism book long time ago but never tried it because it felt too complicated. I actually tried today after watching this video and after 2h it feels so easy to do, thank you so much 👍🏻

[@Roanokewood]

My great grandfather had dimenta. He asked my grandpa (his son) what day he was born. My grandpa told him and he stayed quiet for about 40 seconds and says "you were born on a Monday". He was a smart guy.

[@user-sv5kt8qz3v]

@@user-pe5zv2mm2l lol

[@MaeckesPlanB]

dimenta :D

[@raghvendrasinghsengar8360]

Very realistic story... I can say this by how a father didn't knew his son's birth date...

[@nexus9677]

@@raghvendrasinghsengar8360 He had dementia smart guy

[@cybernerd7492]

@@raghvendrasinghsengar8360 Cambridge wants to know your location

[@GaunteroDimmm]

4:50 it makes me heart feel good that you can still do the Chalk thing.

[@singingbanana]

I love this video!

[@Captopia]

Ayy it’s James Grime! I agree with this vid. Your explanation on Numberphile was great :)

[@vez3834]

Hey James! Thanks for everything you do :)

[@stare4539]

Me too

[@joao13soares]

I just found a new hobby lol. I'm loving the fact that it was so easy to get used to the algorithm after 10 tries. It really was enough to get through all the special cases and tricks that can be used. Awesome! Thanks for this video!

[@plumbersteve]

"Tunnel into the quantum realm" with the dotted chalkline trick. . .very meta. Also, I liked the reverse learn quick scenario of this video. Starting with mastery and working backward to show the process. Great Jorb!

[@DannySullivanMusic]

you're right. unequivocally right!

[@___wij]

Great jorb indeed

[@imalsodontai5677]

@@___wij indeed it was

[@tekwani99]

I was trying to follow along and I completely lost it at "quantum realm" hahahahhaha

[@Narinjas]

4:52

[@pamirsalar]

It was about 15 years ago when I First encountered with this method. There was an elderly guy always sitting in front of a shop watching people passing by. My schoolmates and I used to walk pass him on our way back home. He used to ask us for a random date and would have told us which day it was instantly. I really started appreciating his talent after I read about the method in a math tricks book I got from the library. Not gonna lie, Since then I always felt sorry why such a talented mind has to just sit on a street all day everyday.

[@The_Rising_Dragon]

Your old mate was just Isaac Newton in disguise enjoying his retirement startling the young 'uns! :)

[@1SmokedTurkey1]

Why feel sorry? You don't know if he was enjoying himself or not. Life isn't about accomplishments and "doing". Maybe he was in a bliss we'll never know.

[@umarthegamer]

anime sensei right there. I'm pretty sure he's producing oxford worthy students somewhere out there in a dojo up in the mountains.

[@kalen2]

Wow

[@PopeLando]

@@The_Rising_Dragon I was going to say, "It was John Conway."

[@FuzzyPuddingGamer]

I got into your vids a few months ago and I was amazed! But you seemed to take a short break right after. I'm so stoked that you're back at it again! Keep it up my friend! I'll watch every single vid you put forward. You're an inspiration, I'm already working on my juggling

[@coreyladovsky9735]

Also, awesome material. Thank you so much for making these videos. Always inspiring!

[@whatevermaigret4026]

The only thing I really learned from the video: Mike is left-handed 😂

[@DannySullivanMusic]

haha dude awesome

[@whatevermaigret4026]

@@DannySullivanMusic 🤜🤛

[@jaredf6205]

He should try learning to use his other hand.

[@MJake]

That is impressive!

[@MotivationalLinesQuote]

@emelia omg yrwsz thank you

[@DannySullivanMusic]

yes. unequivocally correct dude

[@stare4539]

Ye

[@matheuscabral9618]

no it’s not, it’s very easy you can learn in less than an hour stop being dumb

[@jovanobates3835]

I just wanted to say. Thank you for being a part of my personal journey in life, Mike. This video put a smile on my face.

[@erickeane471]

I've actually tried nearly all of your stuff. I never did the rollers on the bike because they were expensive, and I'd love a penny-farthing. To date, I can: break an apple in half with my hands, the chalk dots (literally first try), Rubik's cube, Rubik's pyramid, bunny hop, dice stack, card throwing. I've also learned: lots of magic tricks (Chris Ramsey tutorials), riding a unicycle, walking on my hands, coin rolling, cartwheels, 1 handed, then no-handed. 1 thing I cannot do is juggle and it pi**es me right off. Keep up the videos I absolutely love them and love to learn.

[@jaredf6205]

Update on the juggling?

[@heyoyo10gaming4]

@@jaredf6205 He seems to be pretty good at juggling discovering this stuff and learning to do it

[@HappyOrwell]

Epic dude! Keel it up

[@Galleum]

Mike is getting too overpowered 😂

[@jpizzleforizzle]

Mike's too OP! Devs, nerf pls!

[@DannySullivanMusic]

hehehe pro comment

[@theroboman727]

@@jpizzleforizzle yeah put a nerf into the next patch pls

[@Human1136]

Knowledge will increase... Bible spoke about this before it happened..

[@alexfisher4207]

Great to see Mike drawing a dotted line on a chalkboard again 😂

[@catnipcannabis9986]

Ye i noticed as well 😂

[@onewaydrive_]

Yes! I just commented this as well lmao. It was like one of his first videos

[@flowerdolphin5648]

Noticed that too, it was the 1st video I watched of him as well xD

[@Reashu]

I'm more impressed by this than the math!

[@ahmedasigri7703]

There is a guy here in Ghana who calls himself "computer man" he's been doing this for as long as I remember, plus his speed and accuracy is quite legendary. I understand it's mathematical in nature.

[@johnregel]

This reminds me a lot of learning subnetting for computer networks. Being able to determine quickly determine the CIDR or decimal notation of a subnet mask, the available host addresses, etc. is the network engineering equivalent of this lol.

[@SaosinComeClose]

I have enough trouble remembering to breathe, let alone delving into the quantum weekday realm.

[@smashyrashy]

Ok

[@DannySullivanMusic]

lolll very nice

[@1vader]

John Conway (famous mathematician, though to the general public mostly known for Conway's game of life) who invented this method set up his PC so that it would ask him a question like this every time he tried to log in and would only let him pass when he answered it correctly. Eventually, he got so good at this that he was able to do it in under 2 seconds for any date. I heard he was great at parties since he knew quite a few tricks like that.

[@kalen2]

Wow that’s so cool!

[@MarkusAldawn]

We need an app for it. I'd spend bored hours trying to perfect it

[@brotherbumkin3010]

@@MarkusAldawn I'm gonna to make a program to do this maybe not an app but just an exe for myself.

[@TheFyreSA]

@@brotherbumkin3010 would you be willing to share it once it's completed?

[@eravar2831]

@@MarkusAldawn I’m gonna write a script for it to practice

[@antes.8165]

You've inspired me to learn this a couple of day ago. Although I learned it very quickly it will definitely need a lot of technique and practice to get faster. Also, similarly to you, I've made a little program/game for practicing this. Awesome video as always

[@johaneklo9666]

Would love to see your process of working! Awesome video. I sat down a couple of hours yesterday, using your method, and can now tell the day of the week at any given date! Thanks!

[@diamondbandit8385]

My Maths teacher did this on my first lesson with him. He taught us, but I had since forgotten all about it. Thanks for bringing back the magic for me ❤️

[@v1neet]

she even wrote 11 'th' for the Americans who would probably think its 6 November 😂

[@hetsmiecht1029]

The six of Novemberth of course!

[@v1neet]

@@hetsmiecht1029 😭

[@N8ExtrAwesome]

That explanation was amazing! I got lost around the quantum realm, but the dotted line helped me stay with it.

Numberphile is a gift that keeps on giving. So are you, Mike!

[@Rahi0823]

Yep he can still do the "dotted line on a chakboard 4:53

[@_domerta7249]

Just waiting for your comment

[@addisonmiller2222]

It was right here I realized I needed to go back and watch that video.

[@topkinsme8493]

I watched the numberphile vid eariler when it released and I loved this trick! When I saw this title and when you started guessing, I paused and calculated it in my head and unpasued to see if it was right and I was right! Granted I'm still show so I took a minute for each date, but it still felt great!

[@advaykumar9726]

It's okay to be smart also made a video

[@mahiiii2112]

i have a doubt, how to know how many leap years to add 10:41.. i'm really confused please help me

[@topkinsme8493]

@@mahiiii2112 The numberphile video explains everything clearly, but I think we just divide the year number by 4 to get the number of leap years

[@ExtremeMisfit]

Mike! This was fantastic! Grimes is a great presenter and it would be really cool, if you could share the spreadsheet!

[@ZinkZoodles]

Did you ever find the spreadsheet?

[@tobiasvl02]

@@ZinkZoodles i guess not :(

[@shivamgumber]

Yes, you are not good at explaining but I came to know about this through you so keep doing because I am learning new skills because of you.

[@Hyperkatten1]

I really admire your dedication to learn all these random skills!

[@Martinirams]

Kim is such a good audience. Her reaction is great :)

[@PerspectiveInsightReviews]

Thanks for telling us about numberphile's video, i just went and learned it in like an hour

[@raulsukovic5033]

I've learned this and I can tell you it's really cool showing this to people and seeing them looking at you like you're a freaking genius

[@marcosgutierrez1265]

yeah thats called being freaking egotistical

[@lastnamefirstname8655]

this is amazing. impressive skill learned, mike.

[@SophsNotes]

This is amazing, one of the skills you've done that I want to learn the most 😅

[@danne786]

Thank you Mike! This was SO fun to learn!

[@roykoren9260]

I once knew a 5 yo kid that has savant. He can do it without using math. When asked how does he know the day of the week by the date, he said "I just see it in my mind"

[@thilo.friedr]

Such a great video! I'll definetely try it out :D Thanks for your amazing and inspiring videos, Mike (+team) 😀🤩

[@middlemayhem]

coolest part was the dotted line with the chalk lol

[@franksnyder9262]

Just learnt this from the numberphile video because I saw this one, I’m not very fast but it’s extremely pleasing to get it correct

[@ItsIgnatius]

This is the most determined and dedicated man i have ever been blessed to witness

[@bathedinshadow]

I've never seen a date written out in this format. Yeah in the US it's month/day/year. In most other countries, it's day/month/year. So that part isn't odd. But writhing "th" after it but still doing the slash format, is what I've never seen before.

[@AJ_UK_LIVE]

I'm from the UK - no one does that here either haha. She is unique.

[@rabg4774]

@@AJ_UK_LIVE maybe they decided to write it like this due to the global audience. It takes away any of the ambiguity about the date, although I agree I have never seen this before.

[@AJ_UK_LIVE]

@@rabg4774 You may be right. And it does make it easy to understand no matter what.

[@Twas-RightHere]

No doubt they did that to cater to the Americans…

[@bathedinshadow]

@@Twas-RightHere Wouldn't they have just said "December4th 2021" instead? Removes the questioning for the various formats from country to country... and is more common? In the US and Canada this is a common way to verbally say a date. Either way not a big deal. I'd just never seen it. :)

[@alexanderalblas4559]

I knew someone who could tell what day it was, wat he was doing, what was in the news and what weather it'd been on any date you gave him! Absolutely blew my mind

[@ahobbit1273]

I would like to imagine that this trick also applies to the future.

[@kay-c7486]

Your explanation is priceless! Love love

[@jubooty27]

You literally make me want to learn all these things.

[@TrickerShooting]

Alternate Title: "How to properly credit people". Its great that you didn't just encourage your audience to watch the video, you almost require them to by not just summarizing his own work. I can't explain it but this really puts a smile on my face.

[@ashtonsprunger4647]

Hey Mike, I also watched the numberphile video when it came out. You inspired me to learn the skill! Out of curiosity, how long does it usually take you to calculate the day?

[@Medaichi]

Crazy how this studying method can be applied to anything that we do! Speed is the key to mastery!

[@peterbuchanan334]

I’m definitely going to learn how to do this next time I have an exam to study for

[@itsfqndave]

What I learned today: when AI eventually creates the matrix, Mike Boyd will become the chosen one to free us all.

[@JasonTubeOffical]

Or if humans are capable of this, and AI will inevitably be smarter. This only means we can't comprehend how smart they will be :(((

[@secret12392]

“Then you tunnel into the quantum realm” ~Does that chalk dotted line trick~ Why did I find that so funny?

[@tamastorok2443]

I learned this about 3 years ago when I was 10. I am glad You learned it.😀

[@Exiled_Q]

Thanks again Mr. Boyd!!

[@jungleman3321]

3:05 The progression of my math classes' curriculum throughout the year; beginning, easy to follow, end, impossible. 😂

[@samuelcartwright3709]

Learnt this entire skill just to have a chance to finally use a chalk board 4:44

[@pkbreeze08]

I really like this, I feel like I would take far longer than 8h to get this down though. Well done Mike, another string to your bow.

[@markthompson8777]

Heya Mike, I learnt this last night. Thanks for the shoutout to Numberphile’s vid. Would love to see you learn Mongolian throat singing!!

[@jpmnky]

He’s taking the current calendar and factoring in leap years, going backwards. I’m sure at first you’ve got to write it all down. But as he got better he could do it in his head.

[@stevenbridges]

Totally gonna learn this 😂

[@stare4539]

Ye

[@nickroethel3326]

Numberphile is REALLY good at taking complex math and breaking it down simple enough for people to understand

[@20thcenturyremnant]

Nice touch working in your dotted line trick.

[@harveyirvine]

Have you ever seen the female savant twins who can do this ? They don’t follow any math strategy to work it out they just know the date. Really cool

[@VaradMahashabde]

Another method : a year is 365 days =52 weeks + 1 day, so year by year the day count advances by 1, and by 5 in a 4-year block (accounting for leaps). But divided-by-100 years don't have leaps, so that a change of 124 or 5 for 100 years after removing 7s, but divided-by-400s do, so 400 years have a change of 500-3=497 or no change. Things to remember : 1st jan 2000 was a saturday, and that 31-day months advance day by 3, and 30-day months by 2. Feb normally doesn't change as it is 28 days, but +1 in leaps. Go.

[@truffalachubbles2529]

Love how you used the dash chalk skill you learned earlier

[@paintswithlead7517]

amazing video, really nice and to the point. Definitely going to watch the linked video as well.

[@MarkVirgulto]

Worked with a guy with special needs at a home for people with disabilities and he had this ability. We would introduce him to new staff by having them tell their birthday and year and he would think hard and ALWAYS get it right. It was a cool ice breaker. We gave him a fake date once, I believe it was a leap year and day that never existed and after thinking hard as usual he stood up and jumped and said "No, No, No" with a huge smile on his face. Watch the movie Rain Man and it's basically his character. He loved dates and days. Also TV Program guides. Newspapers. A lot of other date related things.

[@GringoJacinho]

Is there anyway you can share this spreadsheet so we can practice?

[@Zorpho86]

Or make a tutorial so we can make it ourself.

[@myro6503]

@@Zorpho86 its not hard, use kzbin.info/www/bejne/bZy1dImmZq6UZ9E and kzbin.info/www/bejne/o6PaiIOwlM2NZ8U to generate the dates and the days

[@toastedbred2961]

love the casual dotted line

[@rashidsuleymanov6479]

Beautiful explanation:D

[@austinpatrick2682]

Honestly I didn't know this was a learnable skill, I guess after seeing rain man do this I just thought it was a thing only a savant could do.

[@nataliesoutlet]

Impressive ✨✨✨

[@dylanplayzmusic]

Hi

[@SimpleUsernameOriginal]

Best channel. Keep it up Mike (and team)

[@PodcastClips.tv385]

im not gonna lie, all your videos are cool but this is probably the only useful trick you've done that i could realistically learn myself. nice video!

[@dailyyy_]

On the 5th of September in 2056, Mike has aquired every skill, what day is that mike?

[@shivambansal42]

That’s my birthday!

[@columbus8myhw]

Tuesday

[@dailyyy_]

@@shivambansal42 thats a big coincidence

[@rvure]

Shivam Bansal whoa that’s pretty cool. Its also pretty cool that I recognized your name as the multi blind ex world record holder.

[@user-sv5kt8qz3v]

@@columbus8myhw chewsday init

[@judecook3409]

He really threw in the dotted lines on the whiteboard for an extra flex

[@stelth3boi897]

Saw this video, learned this trick as quick as i can and it is super

[@knewked899]

3:54 Im more impressed on the way he counted and lift is ring finger without moving his pinky a long with the motion

[@ahmeteris2660]

on god

[@dumflame]

Pretty easy

[@jellez280]

Please share the spreadsheet!! I really want to practice this! Super cool vid :)

[@jellez280]

@Arjun Khemani No :/

[@TheMathias95]

You saw it in the video, just replicate it bruv

[@ZinkZoodles]

Did you ever find the spreadsheet?

[@jellez280]

@@ZinkZoodles nope...

[@ketzi2930]

Bro I was born in 11th of June and I was genuinely terrified

[@florizonefilm]

This is awesome!

[@JaydoS123]

I loved the little dotted chalk reference you had there

[@Adamnuss]

the calendar was changed from Julian to Gregorian in 1752. When looking at days of the week for dates before that, the internet has mixed results. you should try dates before 1000 and see if you get it right. I couldn't. the Doomsdays before 1700 have a pattern of Tue-wed-thu-fri-sat-sun-mon and so on. the pattern we saw on Numberphile was Tue-wed-fri-sun. What do you think?

[@Sandalwoodrk]

are there certain things you've learned that you're more invested in keeping than others? and do you have any tips for maintaining multiple different skills over time

[@elleelleelleelle_______]

I love how excited and intrigued she is right from the start like s child

[@osmia]

I watch that video too. But did not have the gumption to actually try and learn it. Kudos to you!

[@SooDamGood]

Can you link the spreadsheet so we could practice this?

[@GringoJacinho]

Up

[@GringoJacinho]

If you want this too like and comment this comment so he’s more likely to see it

[@ChomeurGlowUp]

I'm facing the issue to generate random dates. Once that unblocked, it's quite easy. I comment to up the message... and maybe find someone who can help?

[@ZinkZoodles]

did you figure it out?

[@SryImHigh]

This is a super cool video, thanks mike. I love your channel because it always gives me an outlet for my anxiety to go and try some of the things you've done in your past videos or try to learn different stuff I'm actually going to go and check out the original video that you recommended at the beginning of this video to see if maybe I can learn myself. That's a cool little trick 🤙🏻🤙🏻🤙🏻

[@buchan7369]

It's really cool to hear that people gain stuff more than just simple enjoyment out of videos like this! Hope all is going well for you.

[@SryImHigh]

@@buchan7369 ty. I appreciate you

[@noahs.627]

This was on my exam thanks mike

[@ehabelmashtoub5261]

Just learned it in a couple of hours that’s amazing

[@flamecrew9atroblox958]

Could you possibly share the spreed sheet?

[@isavalla1935]

I could learn this and someone would pick today’s day and I’d get it wrong

[@mrhappytommy5865]

I was born on a thursday, good vid btw. Just like you i am also an expert with the days of the week. I know about leap years and for example if something like february 11th was on a sunday, that would mean next year it would either be monday or tuesday depending on whether its a leap year. It just contains calculation tbh. So glad we finally got a challenge like this, keep it up!

[@eej9273]

This is cool. Like people who know how to flip a coin and can call it correctly dozens of times in a row. But basically everything you do no matter what is 50/50, either you are right or you are wrong! I like the nerdy stuff though, first time I got excited in school about something was in junior high when the teacher would play this game and just rattle off different things and you would have to raise your hand fast and answer it, she would say 7 times 7 plus 2 divided by 3, and on and on and made them harder, only me and two other kids played and it was fun and competitive and the rest of them just sat there waiting to leave. I also want to learn a language in a few months so I am glad videos are popping up for that type of stuff along with this.