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N5Lesson notes · Oct 3, 2026

Today, Tomorrow and Yesterday in Japanese: 今日きょう・明日あした・昨日きのう and why the kanji don''t match the sounds

Today is 今日きょう (きょう), tomorrow is 明日あした (あした), and yesterday is 昨日きのう (きのう) — and the sounds do not match the kanji, so you have to learn each word as a whole.

If you have tried to sound these out from the kanji, you have already noticed the problem. 今いま is "now" and 日にち is "day," so 今日きょう should be "ima-hi" or "kon-nichi." It is neither. These are three of the most used words in the language, and all three break the normal reading rules on day one. The good news: there are only a handful of them, they come in a tidy ladder, and the grammar around them is simpler than you would expect.

The basics

What are today, tomorrow and yesterday in Japanese?

Three words, one for each day, written in kanji and usually read as shown here.

今日きょうは天気てんきがいいですね。 — The weather is nice today, isn't it? (polite, small talk) 明日あしたは休やすみです。 — Tomorrow is a day off. (polite) 昨日きのう、映画えいがを見みました。 — I watched a movie yesterday. (polite, past tense with 昨日きのう)

Notice that the verb tense does the rest of the work. 昨日きのう goes with the past (見みました), 今日きょう usually goes with the present or a plan, and 明日あした goes with the future (which Japanese writes in the same plain present form).

Why don't the kanji match the sounds?

Because these are jukujikun (熟字じゅくじ訓くん): words where the whole kanji group stands for a native Japanese word, instead of each kanji carrying its own reading. 今日きょう means "this day," and the old native word for it, きょう, got attached to the two characters as a unit. You can read more about this kind of reading in our guide to jukujikun.

The practical rule: do not break these words apart. 日にち is usually にち, び or か in compounds, but inside these three words none of those readings appear. Learn the pair "kanji group → sound" and move on.

How do you say tomorrow: あした, あす or みょうにち?

All three are written 明日あした, and all three mean "tomorrow." The difference is register.

明日あした、会あいましょう。 — Let's meet tomorrow. (everyday, polite, read あした) 明日あしたの天気てんきは雨あめでしょう。 — Tomorrow's weather will probably be rain. (news or forecast voice, often read あす) 明日あしたはお休やすみをいただきます。 — I will be taking tomorrow off. (business or very formal, read みょうにち in some offices)

あした is the default for conversation. あす sounds like an announcer or a written notice. みょうにち is stiff and mostly heard in business Japanese, and many people never say it aloud.

How do you say yesterday: きのう or さくじつ?

昨日きのう is きのう in nearly all speech. さくじつ is the formal reading, heard in announcements, letters and business phone calls.

昨日きのうはありがとうございました。 — Thank you for yesterday. (polite, read きのう) 昨日きのうは大変失礼たいへんしつれいいたしました。 — I apologize for yesterday. (very formal, a business speaker may say さくじつ)

If you are not sure, say きのう. It is never wrong in spoken Japanese, while さくじつ in a casual chat sounds like reading a letter aloud.

What is the full ladder from two days ago to two days ahead?

Memorize it as a line. Each step has its own word, and two of them look nothing like the kanji.

English Kanji Reading Register
two days ago 一昨日おととい おととい everyday (formal: いっさくじつ)
yesterday 昨日きのう きのう casual and polite (formal: さくじつ)
today 今日きょう きょう all registers (formal: 本日ほんじつ, ほんじつ)
tomorrow 明日あした あした casual and polite
tomorrow 明日あした あす news, forecasts, notices
tomorrow 明日あした みょうにち business, very formal
day after tomorrow 明後日あさって あさって everyday (formal: みょうごにち)
three days from now 明々後日しあさって しあさって everyday, a little less common

For counting backward further, such as three days ago or a week ago, see our guide to saying days ago in Japanese.

Beyond the basics

Do you need a particle after 今日きょう, 明日あした and 昨日きのう?

No. In ordinary use they stand alone with no に, and adding one is the most common beginner mistake.

今日きょう、行いきます。 — I'm going today. (polite) 明日あした、学校がっこうに行いく。 — I'm going to school tomorrow. (casual; に belongs to 学校がっこう, not to 明日あした) 昨日きのう、友達ともだちと会あった。 — I met a friend yesterday. (casual)

Compare this with specific dates, which do take に: 三月さんがつ五日いつかに行いきます, 月曜日げつようびに行いきます. The rule of thumb is that relative words (today, tomorrow, yesterday, this week) float free, while fixed calendar points get に. Our post on telling time in Japanese covers the clock-time version of the same pattern.

What are the common time-span patterns?

Three small additions turn these words into deadlines and starting points.

今日中きょうじゅうにやります。 — I'll do it by the end of today. (polite, 〜中なかに = within that period) 明日あしたまでに提出ていしゅつしてください。 — Please submit it by tomorrow. (polite, までに = deadline) 昨日きのうから頭あたまが痛いたい。 — My head has hurt since yesterday. (casual, から = starting point)

Watch the difference between 明日あしたまで and 明日あしたまでに. まで means "continuing until," as in 明日あしたまで待まつ ("I'll wait until tomorrow"). までに means "no later than," a deadline.

Where does こんにちは come from?

It is a leftover from a longer greeting. 今日きょうは (こんにちは) began as the opening of a sentence like "As for today... how are you?", and the rest of the sentence dropped away over time. That is why the greeting is written with は but pronounced わ: the particle never changed its spelling. The same is true of 今晩こんばんは (こんばんは).

こんにちは。 — Hello. (polite, daytime greeting) 今日きょうはいい天気てんきですね。 — Today is nice weather, isn't it? (here 今日きょうは is a real topic, read きょうは)

The two look the same on the page, but one is a fixed greeting read こんにちは and the other is the ordinary word 今日きょう plus は, read きょうは.

What are the this-morning, this-evening and last-night words?

The same ladder idea extends inside the day, and several of these have special readings too.

Word Kanji Reading Meaning
this morning 今朝けさ けさ the morning of today
this evening / tonight 今晩こんばん こんばん evening of today (also a greeting)
last night 昨夜さくや ゆうべ / さくや ゆうべ is spoken, さくや is formal
tomorrow morning 明日あしたの朝あさ あしたのあさ 明朝みょうちょう (みょうちょう) in formal speech

今朝けさは寒さむかったですね。 — It was cold this morning, wasn't it? (polite, small talk) ゆうべ、遅おそくまで起おきてた。 — I stayed up late last night. (casual, 起おきてた is a shortened 起おきていた)

Note that ゆうべ also covers the evening just gone, not only the small hours. For tomorrow morning, 明日あしたの朝あさ is the safe, natural choice.

What about this week, next week and last week?

The same words stretch out with 今いま・来らい・先さき, and these are easier because they follow normal readings.

English Kanji Reading
this week 今週こんしゅう こんしゅう
next week 来週らいしゅう らいしゅう
last week 先週せんしゅう せんしゅう

来週らいしゅう、テストがあります。 — There's a test next week. (polite, no に after 来週らいしゅう)

Like today and tomorrow, these take no に. If you want the "last time, this time, next time" set, see 前回ぜんかい・今回こんかい・次回じかい.

How do these words shorten in texting and speech?

In messages, きょう is very often written in hiragana, because it is faster and feels softer than 今日きょう. あした and きのう get the same treatment among friends.

きょう、ひま? — Free today? (casual text, hiragana for a softer feel) あした何時なんじにする? — What time should we do it tomorrow? (casual) きのうはごめん! — Sorry about yesterday! (casual text)

You will also see あす in written notices, but it almost never shows up in casual chat. If a friend texts you あす, it probably sounds like a store announcement.

How do they sound in anime?

In shounen and slice-of-life anime you often hear a hero close a scene with a determined line about tomorrow, and the word is nearly always あした, in plain casual speech.

明日あしたも頑張がんばろう! — Let's do our best tomorrow too! (casual, the kind of generic rallying line you often hear) 今日きょうこそ勝かつ! — I'm going to win today! (casual, こそ adds "this time for sure") 昨日きのうのことは忘わすれて。 — Forget about what happened yesterday. (casual, a typical emotional-scene line)

Characters who say あす are usually formal ones: a narrator, a butler, a news anchor in a parody scene.

Common mistakes

  • Reading 明日あした as めいにち. The kanji look like they should be めい + にち, and 明日あした is never read this way in everyday speech. The three real readings are あした, あす and みょうにち.
  • Adding に after 今日きょう. 今日きょうに行いきます is wrong in ordinary use. Say 今日きょう行いきます. Only fixed dates and weekdays take に.
  • Mixing up おととい and あさって. Both are two days away from today, and both look alike to beginners. おととい (一昨日おととい) is two days ago, and あさって (明後日あさって) is two days ahead. The kanji help: 一昨日おととい has 昨さく, "past," and 明後日あさって has 後あと, "after."
  • Using あす in casual speech. It is correct, but it sounds like a weather forecast. Between friends, あした is the natural word.
  • Breaking the kanji apart when reading. 今日きょう is not こん+にち in this meaning, and 昨日きのう is not さく+じつ unless you are in a formal setting. Learn each as one word.

Practice

Build each answer before opening it. Questions 1 and 2 are a pair around the particle rule, and questions 5 and 6 are a pair around the two "two days away" words.

1. Say "I'm going tomorrow" using 明日あした and 行いく, in polite form.

Show answer

明日あした、行いきます — 明日あした is a relative day word, so no に follows it.

2. Say "I'm going on Monday." Do you need に?

Show answer

月曜日げつようびに行いきます — weekdays and fixed dates take に, unlike today, tomorrow and yesterday.

3. How is 昨日きのう normally read, and when would you hear さくじつ?

Show answer

きのう in daily speech; さくじつ in formal announcements, letters and business calls. Same kanji, different register.

4. Which reading of 明日あした would you hear in a weather forecast?

Show answer

あす — news and forecasts use あす for a formal, written feel. あした is the everyday word.

5. What does おととい mean, and how is it written?

Show answer

一昨日おととい (おととい) means "two days ago." The 昨さく in the kanji points back to the past.

6. What does あさって mean, and how is it written?

Show answer

明後日あさって (あさって) means "the day after tomorrow." The 後あと in the kanji means "after," so it points forward.

7. Say "Please submit it by tomorrow" with the deadline pattern.

Show answer

明日あしたまでに提出ていしゅつしてください — までに marks a deadline ("no later than"), while まで alone would mean continuing until then.

8. Why is こんにちは written with は but pronounced "wa"?

Show answer

It began as 今日きょうは, "as for today...," and the particle は kept its spelling after the rest of the sentence disappeared.

9. How do you read 今朝けさ and 昨夜さくや in everyday speech?

Show answer

けさ and ゆうべ — both are special readings. 昨夜さくや can also be さくや in formal speech.

In a 30-minute trial lesson, talk about 今日きょう, 明日あした and 昨日きのう and read the kanji aloud, since きょう, あした and きのう have to be learned as whole words.

FAQ

Is today きょう or こんにち? Both exist but they are used differently. 今日きょう is read きょう in ordinary use, as in 今日きょうは雨あめです. こんにち is a formal, written reading that appears in set phrases, and it also sits inside the greeting こんにちは.

Can I say あした and あす in the same way? They mean the same thing, but not at the same moment. あした is for talking, and あす is for announcements, news and written notices. If you only learn one, learn あした.

Why is 昨日きのう read きのう and not さくじつ every time? きのう is the native reading, and さくじつ is the Sino-Japanese reading that sounds more formal. Both are written 昨日きのう, and the setting decides which one you hear.

Do I need に with 今週こんしゅう and 来週らいしゅう? No. Like 今日きょう and 明日あした, they work without に: 来週らいしゅう行いきます. You can add に for emphasis in some sentences, but beginners are safer leaving it out.

How do I say "the day after tomorrow" and "three days from now"? Day after tomorrow is 明後日あさって (あさって), and three days from now is 明々後日しあさって (しあさって). Beyond that, people usually switch to counting days, such as 四日よっか後ご (よっかご).

Vocabulary from this article

Tap the block to select all of it, then copy. In Anki: File → Import, note type Basic, separator Tab, and each line becomes one card.

今日	きょう — today
明日	あした — tomorrow
明日	あす — tomorrow (news, formal)
明日	みょうにち — tomorrow (business)
昨日	きのう — yesterday
昨日	さくじつ — yesterday (formal)
一昨日	おととい — the day before yesterday
明後日	あさって — the day after tomorrow
明々後日	しあさって — three days from now
今朝	けさ — this morning
今晩	こんばん — this evening, tonight
昨夜	ゆうべ — last night
今週	こんしゅう — this week
来週	らいしゅう — next week
先週	せんしゅう — last week
今日中	きょうじゅう — within today
熟字訓	じゅくじくん — words with whole-word kanji readings

I'm Yuuki, a Japanese teacher based in Tokyo. I've taught on italki as a Top 1% teacher and watched over 1,500 anime, so most of the example sentences on this blog come from lines I've actually heard students ask about — including this one, which comes up in nearly every beginner's first few lessons. For practice with feedback, Book a trial lesson · $13, or work through Japanese practice exercises first.

Sources: the author's own lessons and standard reference grammars.

More drills like the ones above, plus a timed JLPT-style mock test: Practice · N5 · Read something at this level: JLPT N5 stories with audio

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