kyou-vs-honjitsu-vs-toujitsu

Japanese has three words for “today” — 今日 (kyou), 本日 (honjitsu), and 当日 (toujitsu) — and each one belongs in a different situation. Using 本日 in a casual text sounds bizarrely formal, while using 今日 in an official speech can come across as sloppy. And 当日 is actually a trap: it does not always mean “today.” This guide clears up the confusion with examples and a decision chart.

Yuka

Hey Rei! I keep mixing up 今日 and 本日 vs. 当日. Can you break it down for me?

Rei

Sure! They’re both useful words but used in different situations. Let me walk you through it with some examples!

At a Glance: 今日 vs. 本日 vs. 当日

今日 (kyou) — Today in Everyday Life

今日 is the standard, all-purpose word for “today.” It is used in conversations with friends, teachers, coworkers, and even in semi-formal situations. It is not rude — it simply is not ceremonial. Think of it as the everyday default for “today” in Japanese.

Note: 今日 has two readings. きょう (kyou) is used in everyday speech. こんにち (konnichi) appears in set phrases like こんにちは (konnichiwa — “good afternoon/hello”). In most situations, read it as きょう.

Example 1 — casual conversation:

今日、学校に行った？
Kyou, gakkou ni itta?
Did you go to school today?

Example 2 — semi-formal:

今日は会社に行きましたか？
Kyou wa kaisha ni ikimashita ka?
Did you go to work today?

Example 3 — personal plan:

今日はピザを食べる予定だ。
Kyou wa piza wo taberu yotei da.
I’m planning to eat pizza today.

Yuka

Oh, so 今日 is used that way! I never thought about it like that.

Rei

Exactly! Once you see it in context a few times, it starts to feel natural. The key is paying attention to 今日 when you read or listen.

本日 (honjitsu) — Today in Formal Settings

本日 also means “today,” but it is the formal, ceremonial version. You will hear it at opening ceremonies, company announcements, official speeches, and formal written notices. Using it in ordinary conversation is not wrong, but it sounds noticeably stiff — like saying “on this day” instead of “today” in English.

A common misconception: some learners think 今日 is rude for superiors. It is not rude at all — it is simply not ceremonial. You can comfortably say 今日 to your boss. Reserve 本日 for official or ceremonial contexts.

Example 1 — speech opening:

本日はお集まりいただき、ありがとうございます。
Honjitsu wa oatsumari itadaki, arigatou gozaimasu.
Thank you for gathering here today.

Example 2 — business announcement:

本日より、新しいサービスが開始されます。
Honjitsu yori, atarashii saabisu ga kaishi saremasu.
Starting today, a new service will begin.

Example 3 — formal written notice:

本日の営業時間は17時までとなります。
Honjitsu no eigyou jikan wa juushichi-ji made to narimasu.
Today’s business hours will be until 5 PM.

Yuka

And what about 本日 vs. 当日? I always thought it was the same as 今日…

Rei

Easy mistake! 本日 vs. 当日 has its own distinct meaning. The difference becomes really clear once you compare them side by side — which is exactly what we’re doing here!

当日 (toujitsu) — The Day Of (Not Always Today!)

当日 is the most misunderstood of the three. It does not always mean “today” — it means “the day in question” or “on that day.” It is used when referring to the specific day of an event, appointment, or occasion. That day might be today, tomorrow, or three weeks from now.

Common uses include event day logistics (“on the day of the event”), same-day reservations (“same-day booking”), and rules that apply on the day itself (“on the day, please bring your ID”).

Example 1 — event day:

当日は早めに会場に来てください。
Toujitsu wa hayame ni kaijou ni kite kudasai.
Please come to the venue early on the day of the event.

Example 2 — same-day ticket:

当日券はまだありますか？
Toujitsu-ken wa mada arimasu ka?
Are there still same-day tickets available?

Example 3 — instruction for a future date:

試験当日は、証明書を持参してください。
Shiken toujitsu wa, shoumeisho wo jisan shite kudasai.
On the day of the exam, please bring your ID.

Side-by-Side Comparison

Decision Flowchart: Which Word for “Today”?

Are you talking about a day?
        |
        v
Is it referring to a SPECIFIC EVENT DAY
(the day of an appointment/event/exam)?
   |           |
  YES          NO
   |           |
   v           v
Use 当日       Are you in a FORMAL/CEREMONIAL context?
(e.g., 当日券  (speech, official notice, announcement)
試験当日)       |           |
               YES          NO
               |            |
               v            v
           Use 本日        Use 今日
           (formal today) (everyday today)

Quick Quiz — Test Yourself!

Yuka

Okay, I feel a lot more confident about 今日 and 本日 vs. 当日 now! Should we test it with a quiz?

Rei

Let’s do it! A quick quiz is the best way to make sure the difference really sticks.

Fill in the blank with 今日, 本日, or 当日.

Q1. What are you doing today? (casual text to a friend)
＿＿＿、何してる？
___, nani shiteru?

Answer: 今日 (kyou)
Reason: Casual conversation between friends — 今日 is the natural everyday word.

Q2. Thank you for joining us today. (opening of a formal ceremony)
＿＿＿はご参加いただきありがとうございます。
___ wa gosanka itadaki arigatou gozaimasu.

Answer: 本日 (honjitsu)
Reason: Formal speech at a ceremony — 本日 is the standard ceremonial word.

Q3. On the day of the concert, the gates open at 6 PM.
コンサート＿＿＿は、18時に開場します。
Konsaato ___ wa, juuhachi-ji ni kaijou shimasu.

Answer: 当日 (toujitsu)
Reason: Referring to the specific day of the event — 当日 is the correct choice.

Q4. Today’s special is grilled salmon. (restaurant sign)
＿＿＿のおすすめは鮭の塩焼きです。
___ no osusume wa sake no shioyaki desu.

Answer: 本日 (honjitsu)
Reason: A formal written notice at a restaurant — 本日 is commonly used in business signage.

Q5. You cannot cancel your reservation on the day itself.
＿＿＿のキャンセルはできません。
___ no kyanseru wa dekimasen.

Answer: 当日 (toujitsu)
Reason: Referring to same-day cancellation — 当日 is the standard term for “the day of.”

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