© 2012 niall. All rights reserved.

samurai | how many days in a month?

The other day someone asked me how you remember the number of days in the months in English. We use this little rhyme. It sounds very old. The rhyme one with alone could come from Shakespeare.

Thirty days has September
April, June and November
All the rest have thirty-one
Except February alone

I found that there is a mnemonic using knuckles too. When you count out all the months though there are a couple of knuckles left over so – no. There has to be a more satisfactory solution.

In Japan they use a very short sentence:


nishi muku samurai

2   4    6   9   11

Ni shi mu and ku are ways of pronouncing 2 4 6 and 9. That’s called goroawase. I talked about it briefly in tokyo sky tree.

Samurai is not the usual kanji for samurai 侍. It’s the shi 士 from bushi 武士, another word for samurai. It’s also used as a suffix meaning scholar in words for professions like bengoshi – lawyer – and keirishi – accountant. The Japanese letter 士 looks like the letters for ten 十 plus one 一. Or eleven.

So Japanese people remember that all the months have 31 days except the second, fourth, sixth, ninth and eleventh.

So wow. I look at it in admiration. Short, elegant and cool. Perfect. You probably won’t forget it now either.


article about this mnemonic


cool illustration: Prayer /// Red Vector Thoughts by Vector Hugo


  1. niall

    Thanks Carina. There’s a longer version of the English rhyme including February. The Japanese version is nice and concise!

  2. Wow, very nice post, thanks Niall, we use also the knuckles but only from one hand, so when you are counting the last, you begin again with same(July/August) or a rhyme similar to the english one:
    “Treinta días tiene Noviembre con Abril, Junio y Septiembre, veintiocho sólo hay uno y los demás treinta y uno”

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