
Palindrome Day 20200202 - stanislavb
https://blog.sumymus.de/palindrome-day-20200202
======
susam
The nice thing about today's date, 2020-02-02, is that it is palindrome in
three date formats: YYYYMMDD, DDMMYYYY, and MMDDYYYY.

This should probably be called "Universal Palindrome Day" because it is a
palindrome irrespective of the endianness (big, little, or middle) that is
used in various countries.

Here is the list of all such dates until the year 9999:

    
    
      0101-10-10
      1010-01-01
      1111-11-11
      2020-02-02
      2121-12-12
      3030-03-03
      4040-04-04
      5050-05-05
      6060-06-06
      7070-07-07
      8080-08-08
      9090-09-09
    

The next such one is over 101 years away from now.

Here is my own blog post on this topic: [https://susam.in/blog/universal-
palindrome-day/](https://susam.in/blog/universal-palindrome-day/) :-)

~~~
skrebbel
I love the term "middle endianness" and how clearly it highlights how nuts the
American date notation is.

EDIT: fwiw, in my native language, most numbers from 100 and 1000 are
pronounced middle endian, so I'm not complaining.

~~~
thaumasiotes
The American date notation is simply a direct reflection of the spoken
language. We say "February second, 2020" and we write "2/2/2020". (Contra the
root comment, I can't agree that 2/2/2020 is a palindrome.) I don't see this
as being crazy or even unusual.

When order matters, you invariably want big-endian notation, which is why that
notation is acceptable everywhere regardless of the usual native notation. But
by the same token, it means that all other styles are equally "nuts". European
day-month-year notation doesn't have any technical advantages over month-day-
year.

~~~
hibbelig
That middle-endianness is spoken doesn’t make it better. It’s still crazy.

Starting with the most general and ending with the most specific is a logical
order. Doing it the other way round is also logical. But starting with the
middle makes no sense.

It doesn’t seem unusual to you because you use it often.

That said I’m German and I realize that German postal addresses are crazy for
the same reason. I wish we‘d adopt the Chinese format: country first then
province (state), then County then town then neighborhood then street and
house.

German addresses are middle endian: street then house number then zip code
then city then country. The right order seems to be: city, zip, street, house
number. Most general to most specific.

~~~
mopsi
What's so crazy about the German notation? Seems to make perfect sense, as it
goes line-by-line from the smallest to the largest sorting unit:

1\. Exact street location (street + house)

2\. District (postal code)

3\. City

4\. Country

Also I prefer this order over the Chinese, because I assume most people
handling mail will need to smallest details and it would just be very annoying
if local mailmen had to skip over country and city names every time before
reaching the bit they actually need.

~~~
hibbelig
The house number is smaller than the street, but the street comes first. If we
put the house number first, then we'd get a logical order.

~~~
Kaiyou
You're thinking of street and house number as two things. Germans don't. Or at
least I don't. Your approach makes as much sense as picking movie titles with
numbers at the end apart into two things.

~~~
jgwil2
Street and house number are certainly two different things. It's more like
series of movies (Die Hard 1, Die Hard 2, etc. are different movies but part
of the same series. In the same way, a street could be seen as a series of
houses or addresses. So the smallest unit is the house, then the street.

~~~
Kaiyou
Yes, it's like a movie series. It's Die Hard 2. That's one name, not two, "2"
and "Die Hard", but one: "Die Hard 2".

~~~
jgwil2
I didn't say it was two names, I said there are two different movies within
the Die Hard series. Just like two different houses on the same street.

~~~
Kaiyou
Yes, but each movie is a single entity and the number is part of that entity.
Just like with "street+house number". It's one entity, not two.

------
hkmurakami
I hope this is pointed out to kids in classrooms all over the world. Growing
up I remember my teachers would point out these cute number tricks/events
which contributed to piquing my interest in math and numbers, and eventually
engineering.

~~~
lostlogin
> I hope this is pointed out to kids in classrooms all over the world.

For at least some of them it’s the summer holidays and they are heat addled
and doing something completely mindless with no idea of the day or date. I’m
rather jealous.

~~~
whoopdedo
Also, it's Sunday.

~~~
syndacks
Superbowl* Sunday

------
bartkappenburg
Also: it’s day 33 (palindrome) of the year and we have 333 (palindrome) days
left.

------
arthurfm
02/02/2020 is the most palindromic date ever.

[https://youtu.be/4fE_sXZjxng](https://youtu.be/4fE_sXZjxng)

Not only that, but it's a strobogrammatic number when viewed on a 7-segment
display.

~~~
CraftThatBlock
What is "most palindromic"? Wouldn't 11/11/1111 be the "most"?

~~~
qndreoi
The video notes that it is also the 33rd day of the year and 333 days remain.
Thus another palindromical event.

------
DonHopkins
It's finally the year of the DECSYSTEM-2020! It was so far ahead of its time.

[https://en.wikipedia.org/wiki/DECSYSTEM-20](https://en.wikipedia.org/wiki/DECSYSTEM-20)

------
toyg
And it’s my birthday. I always joked that my birthday was US-proof (I’m not
American), but this year it’s extra-special.

~~~
Insanity
A happy birthday to you!

------
pkamb
Today is my son's due date! I've been hoping for months that he'll be here on
time for this palindromic birthday, but nothing yet...

~~~
toyg
Eh man, can’t do much about these things. I was born on 02/02, married on
05/05, first child on 07/07, but the second child “broke the chain” with a
21/11... ️

~~~
KitDuncan
happy birthday!

------
jyap
There’s also coming up: 02/02/2020 02:02:20.20

~~~
NKosmatos
For us located in EU it’s at 20:20:02:02 in the evening :-)

------
FlyMoreRockets
Depending on how you write your dates, 20211202 is the next one.

~~~
AnimalMuppet
And, if you write your dates that way, what will the one after that be?
30100103?

~~~
RandomBacon
In a thousand years, we might be on yet another calendar system.

[https://en.wikipedia.org/wiki/List_of_calendars](https://en.wikipedia.org/wiki/List_of_calendars)

~~~
runj__
I think we already are using another calendar system! Most used dates in
existence are probably using Unix time, at least I know I only check the
calendar a few times a day but I have systems running checking it multiple
times per second.

------
SimeVidas
For once, I found out about this early in the morning instead of the day
after.

------
mcshicks
For those in the US, also groundhog day and superbowl sunday (american
football championship).

~~~
strictnein
> superbowl sunday (american football championship).

And for many it's "watch a bunch of ads with budgets in the $5-10+ million
range" day.

~~~
clSTophEjUdRanu
[https://fivethirtyeight.com/features/how-much-football-is-
ev...](https://fivethirtyeight.com/features/how-much-football-is-even-in-a-
football-broadcast/)

------
nexuist
It's also my 21st birthday! So close.

~~~
toyg
Happy birthday! Same for me, although my years are almost exactly twice yours.

------
JacobAldridge
I remember where I was at 8.02 pm (2002) on 02/02/2002 - on the phone to my
mum, who was in a different timezone so couldn’t enjoy that palindromic
minute.

Sadly I slept through 0202 this morning...

------
bmn__
FTA:

> Because of the Gregorian Calendar Reform of 1582, the numbers of days after
> 1001-01-01 are fictitious, strictly spoken. They are valid only then, if we
> adopt the reform for dates before 1582, subsequently.

The explanation is muddled. This concept has a name, the definition at WP is
succinct and clear:
[http://enwp.org/Proleptic_calendar](http://enwp.org/Proleptic_calendar)

------
aoloe
for those who slept in, 05.05.2020 is coming soon... the mirrored day...

------
geocrasher
This post would not be complete without The Ballad of Palindrome by Riders In
The Sky:

[https://www.youtube.com/watch?v=xzvQEstC03o](https://www.youtube.com/watch?v=xzvQEstC03o)

A Spaghetti Western style story, starring your hero, Palindrome.

~~~
isoskeles
How would this be a Spaghetti Western rather than just an American Western?

~~~
toyg
In some quarters, “spaghetti” has just become a derogative term meaning “low
quality”. Sadly, the concept that “spaghetti western” was actually a genre
with certain characteristics but containing a number of masterpieces, was lost
under the wave of poor clones of The Good, The Bad and The Ugly.

------
threatofrain
Project Euler palindrome problem.

[https://projecteuler.net/problem=4](https://projecteuler.net/problem=4)

------
gabyn
There will be lots of palindromes coming
up:20211202,22200222,21211212,22011022,22211222...

------
Theorance
There is also the 20th of February.

20200220 yy/mm/dd

02202020 mm/dd/yy

20022020 dd/mm/yy

------
punnerud
02-02-2020 also work (02022020)

------
2easy
Happy birthday to me!

------
freyir
The Human Palindrome will be born tomorrow and die on 2121-12-12 at the age of
101. And in true palindromic fashion, his life will start and end with
diapers.

~~~
mcv
Any responsible parent will call him Bob or Anna, of course. Taking surnames
into account is going to be a bit harder.

Here's a good resource for anyone becoming a parent today:
[https://parentinghealthybabies.com/palindrome-
names/](https://parentinghealthybabies.com/palindrome-names/)

~~~
ewindal
Oof, that list is terrible. Natan is listed twice, and there’s at least one
name that isn’t a palindrome. The only two names that really work from that
list is Anna and Hannah. Nobody should name their kid Bob in 2020, it’s not a
«young» name yet. Thr older Bobs need to die off before it’s an acceptable
kid’s name.

As for the rest of those names, I refuse to acknowledge them as names. They’re
more like onomatopoeia.

~~~
dkersten
Ada, Ava, Eve and Viv are all names I’ve seen in the wild and would consider
reasonable names too. There’s also nothing wrong with Bob, despite what you
seem to think. So together with Anna and Hannah, that’s 7 names.

~~~
mcv
All of you are just talking about American name fashions. The point of
20200202 is that it's a palindrome in every single country and culture that
uses AD and the Gregorian calendar. Many of these names may be very suitable
in other cultures.

