## 1595: "30 Days Hath September"

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WilliamLehnsherr
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### 1595: "30 Days Hath September"

Alt text: There's a cool mental calculation hack I recently learned for this: If you open the calendar app on your phone or computer, the highest-numbered box along the bottom is equal to the number of days in the month!

I've always said "30 days has September..." Of course, it's Sptember that has 30 days. 30 days don't possess September, yet...

Sofie
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### Re: 1595: "30 Days Hath September"

Count on your knuckles. Up is 31, down is less. Up January - down February - up March - down April - up May - down June - up July - switch hands, up August - down September - up October - down November - up December.

keithl
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### Re: 1595: "30 Days Hath September"

If we launch a WHOLE BUNCH of mass EASTWARD, we can slow the earth's rotation enough to have exactly 30 days per month. Of course, we will have to add leap seconds every minute or so, because we don't want to redefine the second.

And we should slingshot the mass past the back of the moon - that will slow down the moon, until it orbits in exactly 30 days. That will bring the Muslim calendar in line with the rest of the world, resulting in global peace.
Last edited by keithl on Mon Oct 26, 2015 7:20 am UTC, edited 1 time in total.

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### Re: 1595: "30 Days Hath September"

I still catch myself from time to time tipping knuckles*, but since I broke a metacarpal bone (which did not adhere straight), May's day #31 is highly contested.

*For each month tip a knuckle or a gap. Turn back on the last knuckle, tipping it twice. Every knuckle marks a month with 31 days, every gap a month with less than 31 days.
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Rossegacebes
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### Re: 1595: "30 Days Hath September"

I am also a knuckle-counter. My grandmother taught me very early, and by the time a friend tried to impress me with the 'verbal help', I could show him that my method was far simpler, and robust.
Last edited by Rossegacebes on Mon Oct 26, 2015 1:01 pm UTC, edited 1 time in total.

Montago
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### Re: 1595: "30 Days Hath September"

I still dont understand why we havent implemented the 13 month / 28 day calendar yet ??

13 * 28 = 364

then every year we relax and chill for 1 day
every 4 years we relax and chill for 2 days

and EVERY FREAKING person on earth would know what date each week-number would have and everyone would know what day-of-week each date would have...

i dont get it... whyyyy do we keep this shitty Gregorian calendar ?

orthogon
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### Re: 1595: "30 Days Hath September"

WilliamLehnsherr wrote:I've always said "30 days has September..." Of course, it's Sptember that has 30 days. 30 days don't possess September, yet...

hath is just an older form of has, isn't it? Do you mean have?

Anyone come across that awesome integer arithmetic algorithm that converts days (since some epoch) into dates? Somehow it manages to take into account the unequal months (and possibly the leap years too) in a surprisingly small number of operations. Self-documenting it ain't, however.
xtifr wrote:... and orthogon merely sounds undecided.

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### Re: 1595: "30 Days Hath September"

But why do such things?
look at this, the month number in binary:
0001 - 31 January
0010 - 28/9 February
0011 - 31 March
0100 - 30 April
0101 - 31 May
0110 - 30 June
0111 - 31 July
1000 - 31 August
1001 - 30 September
1010 - 31 October
1011 - 30 November
1100 - 31 Decembrer
Do a XOR of the underlined bits. If it's 1 the month has 31 days. It it's 0 it doesn't.

Or in BCD:
0000 0001 - 31 January
0000 0010 - 28/9 February
0000 0011 - 31 March
0000 0100 - 30 April
0000 0101 - 31 May
0000 0110 - 30 June
0000 0111 - 31 July
0000 1000 - 31 August
0000 1001 - 30 September
0001 0000 - 31 October
0001 0001 - 30 November
0001 0010 - 31 Decembrer
Do a XOR of the three underlined bits. Result is the same.
(I programmed a digital clock once)
Last edited by balthasar_s on Mon Oct 26, 2015 8:32 am UTC, edited 1 time in total.
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orthogon
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### Re: 1595: "30 Days Hath September"

This is the integer division thing I was talking about. I love the way it seems to make sense to begin with, with recognisable numbers like 52 and 365... but then you start getting crazy shit like 306 and 10.

I found the link on a stackoverflow page - somebody asks "do you have a proof of this?", to which the poster replies "what do I look like, Euclid or something?"
xtifr wrote:... and orthogon merely sounds undecided.

da Doctah
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### Re: 1595: "30 Days Hath September"

Just heard, on last week's Dr Demento show (special topic: Insanity) the original of a version of this poem we used when I was a kid. Here's the one from Napoleon XIV's "I'm in Love with My Little Red Tricycle":

Thirty days hath Septober,
April, June, and no wonder!
All the rest have peanut butter,
All except my dear old grandmother.
She had a little red tricycle.
I stole it!

The one we did in my formative years:

Thirty days has September,
April, June, and no wonder.
All the rest eat peanut butter,
Except Grandma and she drives a Buick.

And then there's the zen option:

Thirty days hath September.
All the rest I can't remember.

Wooloomooloo
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### Re: 1595: "30 Days Hath September"

Montago wrote:I still dont understand why we havent implemented the 13 month / 28 day calendar yet ??
i dont get it... whyyyy do we keep this shitty Gregorian calendar ?

Not that I'm entirely opposed to the idea, but why don't you try starting with something much simpler - like abolishing daylight savings time...? Baby steps...!

ucalegon
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### Re: 1595: "30 Days Hath September"

Here's a poem I wrote a couple of years ago which is a little more accurate and useful (sometimes):

If your month is odd and less than eight
Thirty one days you'll have to wait
If your month is odd and more than seven
It's nineteen days, plus eleven

The inverse of each of these is true
Except of course month number two
Which has twenty eight days every year
Except those which by four divide clear

Unless the year ends in double o
When four hundred must also equally go
If you're still not sure what to do with Feb
Just look it up on the World Wide Web.

WilliamLehnsherr
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### Re: 1595: "30 Days Hath September"

orthogon wrote:
WilliamLehnsherr wrote:I've always said "30 days has September..." Of course, it's September that has 30 days. 30 days don't possess September, yet...

hath is just an older form of has, isn't it? Do you mean have?

I thought hath was the inverse of has/have. As in I have a laptop (I am in possession of it), and this laptop hath me (the laptop is in my possession). But by the looks of things I've pulled that completely out of my arse.

Either way, you're quite right. It should be have. I'm still going to use "has". What are you going to do about it?

orthogon
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### Re: 1595: "30 Days Hath September"

WilliamLehnsherr wrote:
orthogon wrote:
WilliamLehnsherr wrote:I've always said "30 days has September..." Of course, it's September that has 30 days. 30 days don't possess September, yet...

hath is just an older form of has, isn't it? Do you mean have?

I thought hath was the inverse of has/have. As in I have a laptop (I am in possession of it), and this laptop hath me (the laptop is in my possession). But by the looks of things I've pulled that completely out of my arse.

Either way, you're quite right. It should be have. I'm still going to use "has". What are you going to do about it?

No, I checked just to be sure, and hath is indeed an archaic form of the third person singular present indicative of have, whose modern form is has. It's not the inverse. However, English used to have more flexibility in word order because of its case system; as the endings of verbs and declensions of nouns got simplified in modern English the Subject-Verb-Object (SVO) order became more important as an indicator of who did what to whom. "Thirty days hath [has] September" is OVS order; it's unambiguous because the 3rd singular verb ending means that September, and not Thirty Days, must be the grammatical subject. In late modern English it should be "Thirty days has September". You are correct, and therefore I'm not going to do anything about it!
xtifr wrote:... and orthogon merely sounds undecided.

bayerf
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### Re: 1595: "30 Days Hath September"

Another simple hack:

Look at a piano keyboard, 12 keys in an octave, 12 months in a year, starting chromatically at
F = january, white (long) keys correspond to long months, short keys to short months. So simple!

førtito
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### Re: 1595: "30 Days Hath September"

I am wondering what day he is speaking of? 24h days? Siderial days? Or the famous 28h days? https://xkcd.com/320/

Xenomortis
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### Re: 1595: "30 Days Hath September"

I never remembered that rhyme - when I was younger I never saw the point, why not just make the effort to learn the facts themselves rather than learn some equally arbitrary rhyme.
Of course I never did that either, so now I just say "I think September has 30 days".

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### Re: 1595: "30 Days Hath September"

I have used this mimetic so many times that all I need to remember these days is "30, September, April, June, November" and I just know how many days are in each month.
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da Doctah
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### Re: 1595: "30 Days Hath September"

Primes less than 1²: none.
Primes less than 2²: 2,3. Two of them. Two = February.
Primes less than 3²: 2,3,5,7. Four of them. Four = April.
Primes less than 4²: 2,3,5,7,11,13. Six of them. Six = June.
Primes less than 5²: 2,3,5,7,11,13,17,19,23. Nine of them. Nine = September.
Primes less than 6²: 2,3,5,7,11,13,17,19,23,29,31. Eleven of them. Eleven = November.
Primes less than 7²: 2,3,5,7,11,13,17,19,23,29,31,37,41,43,47. Fifteen of them. There's no 15th month.

That gives you all the ones that don't have 31 days. Easy peasy.

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### Re: 1595: "30 Days Hath September"

I've never had any trouble with this mental loop. Other mental loops, sure, but not this one.
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rmsgrey
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### Re: 1595: "30 Days Hath September"

My problem has always been with the mnemonic not being memorable enough - I keep wanting to go "April, May" rather than "April, June". By the time I've sorted out which of the two should follow April, I've figured out which months are which lengths from knowing the general pattern.

higgs-boson
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### Re: 1595: "30 Days Hath September"

da Doctah wrote:Primes less than 1²: none.
Primes less than 2²: 2,3. Two of them. Two = February.
Primes less than 3²: 2,3,5,7. Four of them. Four = April.
Primes less than 4²: 2,3,5,7,11,13. Six of them. Six = June.
Primes less than 5²: 2,3,5,7,11,13,17,19,23. Nine of them. Nine = September.
Primes less than 6²: 2,3,5,7,11,13,17,19,23,29,31. Eleven of them. Eleven = November.
Primes less than 7²: 2,3,5,7,11,13,17,19,23,29,31,37,41,43,47. Fifteen of them. There's no 15th month.

That gives you all the ones that don't have 31 days. Easy peasy.

Yuck, great! But for me, that may be effective, but not efficient.

On a nit-picking side note: With the exeption of February all months have 30 days.
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cellocgw
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### Re: 1595: "30 Days Hath September"

Rossegacebes wrote:I am also a knuckle-counter. My grandmother taught me very early, and by the time a friend tried to impress me with the 'verbal help", I could show him that my method was far simpler, and robust.

Hey, I'm polydactylic [not really], you insensitive clod!
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Valarya
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### Re: 1595: "30 Days Hath September"

Came here to add that I'm a knuckle counter.
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detherk
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### Re: 1595: "30 Days Hath September"

Every other month has 31 or 30 days.
Then there is Feb with 28 or 29.

The exception to the numbering happens with the "Caesars"....Julius and Augustus, which both have 31 days.
So odd-numbered months before those have 31 days. Even-numbered months after those have 31 days.
Last edited by detherk on Mon Oct 26, 2015 12:59 pm UTC, edited 1 time in total.

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### Re: 1595: "30 Days Hath September"

I have no trouble remembering the number of days in each month, even without some memory trick like knuckles or poems. I do, however, make it all the way to June before using the correct year the first time when dating things.

Hafting
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### Re: 1595: "30 Days Hath September"

Rossegacebes wrote:I could show him that my method was far simpler, and robust.

Works with all languages too, unlike most poems.

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### Re: 1595: "30 Days Hath September"

higgs-boson wrote:I still catch myself from time to time tipping knuckles*, but since I broke a metacarpal bone (which did not adhere straight), May's day #31 is highly contested.

*For each month tip a knuckle or a gap. Turn back on the last knuckle, tipping it twice. Every knuckle marks a month with 31 days, every gap a month with less than 31 days.

Hmmm ... I didn't remember hearing about tipping knuckles, so I copied "tip a knuckle" (with the quotes) over to google. It found only a few hits, several links to this discussion, some to text that had the phrase split by a period, comma or semicolon, and a bunch of the form "Slipping a hand down between her thighs, a finger tip a knuckle deep into her parting slit, he continues staring her directly into her eyes ...".

So what does it mean? I know about tipping buckets and tipping cows, but I don't know how you might tip a knuckle. It's not something a dictionary is much help with, and searching doesn't decode it, either. Somehow, I don't think that it refers to inserting fingers into parting slits.

Like others, I heard the silly poem about month lengths when I was little, and just remember the line "September, April, June, and November" (maybe without the Oxford Comma, depending on mood). Nothing else really seems needed. I do like some of the weird numerological schemes, though, even if they are harder to apply quickly than that phrase.

Valarya
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### Re: 1595: "30 Days Hath September"

bayerf wrote:Another simple hack:

Look at a piano keyboard, 12 keys in an octave, 12 months in a year, starting chromatically at
F = january, white (long) keys correspond to long months, short keys to short months. So simple!

I've been playing the piano my entire life and have never heard this 'hack.' I love it!
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WilliamLehnsherr
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### Re: 1595: "30 Days Hath September"

This thread is seriously the first time I've ever heard of this knuckle counting technique. Took me a while to figure out how it works (because I'm stupid).

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### Re: 1595: "30 Days Hath September"

bayerf wrote:Another simple hack:

Look at a piano keyboard, 12 keys in an octave, 12 months in a year, starting chromatically at
F = january, white (long) keys correspond to long months, short keys to short months. So simple!

Ooh, this could be useful once I start carrying a piano around. And learn which key is F.

armandoalvarez
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### Re: 1595: "30 Days Hath September"

Montago wrote:i dont get it... whyyyy do we keep this shitty Gregorian calendar ?

Because convincing 190some countries to do much of anything is really, really hard. And because the current system works just fine for most applications other than figuring out what day of the week X day, Y month, Z year will be, and we have calendars for that.

Flumble
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### Re: 1595: "30 Days Hath September"

When I don't know the number of days instantly, I usually count the distance (in months) to New Year: if it's an even number, it has 31 days, if it's odd, it has 30 days... except when it's February of course. It requires you to know the order of the months in two directions, but that's useful to know by heart anyway.

Knuckle-counting is my second favourite.

airdrik
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### Re: 1595: "30 Days Hath September"

I just remember that every other month has 31 days, skipping of course Nerus, the month named after the tyrant Nero and inserted between the months of July and August, but was removed from all calendars.

jpm8766
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### Re: 1595: "30 Days Hath September"

Alt text: There's a cool mental calculation hack I recently learned for this: If you open the calendar app on your phone or computer, the highest-numbered box along the bottom is equal to the number of days in the month!

Windows users caution: this is frequently not true as the calendar widget from the sys tray likes to put a full week from the following month in the last line.

CharlieP
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### Re: 1595: "30 Days Hath September"

Wooloomooloo wrote:
Montago wrote:I still dont understand why we havent implemented the 13 month / 28 day calendar yet ??
i dont get it... whyyyy do we keep this shitty Gregorian calendar ?

Not that I'm entirely opposed to the idea, but why don't you try starting with something much simpler - like abolishing daylight savings time...? Baby steps...!

I like Daylight Saving (not Savings) Time!

Let's revert to the year starting in March - that way September, October, November and December mean something again, and the fiddly month is right at the end.
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### Re: 1595: "30 Days Hath September"

I always wondered why the mnemonic went on like that, because it felt like a hack to remind people of how leap years work, which should be obvious.

I was born in February, so my version was always

30 days hath September,
April, June, and November.
31 for all the rest
But February, because it's best.

I also sometimes switched September and November, because the rhyme and meter stay the same but now they go in chronological order.
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San Fran Sam
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### Re: 1595: "30 Days Hath September"

This is the song that never ends.
It goes on and on my friends.
Someone started singing it not knowing what it was,
And they'll continue singing it forever just because....

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### Re: 1595: "30 Days Hath September"

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### Re: 1595: "30 Days Hath September"

San Fran Sam wrote:This is the song that never ends.
It goes on and on my friends.
Someone started singing it not knowing what it was,
And they'll continue singing it forever just because....

This is the song that ends.
He/Him/His