までに “by ~” / “no later than ~” — expressing a deadline by which something must be completed
【Meaning】 Used to express that an action must be completed, or a state must be achieved, at some point before a specified time limit. The key idea is that the action can happen at any point within the available window — but must be finished no later than the stated deadline. The exact timing within that window is flexible; the endpoint is not.
Note: This is the defining characteristic of までに that makes it distinct from other time expressions. までに does not specify when within the period the action happens — only that it must happen before the boundary. Whether you complete it one month early or five minutes before the deadline, までに is satisfied equally. What it will not tolerate is crossing the line.
【English Translation】 “by ~” / “no later than ~” / “before ~” Expresses that an action must be completed before or at the moment of a specified deadline.
Note: In English, “by” and “before” are close but not identical. “By Friday” includes Friday itself; “before Friday” excludes it. Japanese までに functions like “by” — the deadline moment itself is included as an acceptable completion point. This is worth noting when translating carefully.
【Conjugation】
| Form | Construction | Example |
| Specific time | Time noun + までに | 5時までに — by 5 o’clock |
| Specific date | Date + までに | 金曜日までに — by Friday |
| Verb (plain form) | V (dict. form) + までに | 始まるまでに — before it begins |
| Noun (event) | N + までに | 試験までに — by the exam |
Note: When a verb precedes までに, it is always in the dictionary (non-past) form, regardless of the tense of the overall sentence. 「映画が始まるまでに席についてください」uses 始まる, not 始まった, even though the instruction is given before the event. This is because までに refers to the boundary point itself, which is always framed as upcoming from the action’s perspective.
【The Core Distinction — までに vs. まで】
This is the single most important distinction at this level of Japanese grammar, and one that causes persistent confusion even among intermediate learners. The difference is not merely grammatical — it reflects a fundamentally different relationship between an action and time.
〜まで — “until ~” (the action continues throughout) 「図書館は9時まで開いています。」 “The library is open until 9 o’clock.” → The state of being open continues from now all the way to 9 o’clock. The action or state is ongoing and fills the time up to the boundary.
〜までに — “by ~” (the action is completed before the boundary) 「本を9時までに返してください。」 “Please return the book by 9 o’clock.” → The returning happens at a single point in time — and that point must fall before 9 o’clock. The action does not continue; it is completed once.
The diagnostic test: ask yourself whether the action is ongoing or completed. If the action or state fills the entire period leading up to the deadline, use まで. If the action is a single completion that must happen before the deadline, use までに. Put simply — まで is for duration, までに is for deadlines.
【Similar Grammars & Key Differences】
〜までに vs. 〜までに vs. 〜前に vs. 〜以内に
① 〜まで — Ongoing action or state continues up to the boundary point. 例：雨が止むまで、ここで待ちましょう。— Let’s wait here until the rain stops.
② 〜までに — Single action must be completed before the boundary point. 例：雨が止むまでに、計画を立てましょう。— Let’s make a plan before the rain stops.
③ 〜前に — “Before ~” in a general sequential sense. Less emphasis on a strict deadline, more on the order of events. The boundary is softer and less urgent. 例：寝る前に、歯を磨いてください。— Please brush your teeth before going to sleep.
④ 〜以内に — “Within ~” — expresses that an action must happen within a set duration of time from a starting point. The focus is on the length of the window, not its endpoint. 例：30分以内に返事をします。— I will reply within 30 minutes.
A useful way to remember the family: まで watches the road. までに watches the finish line. 前に describes order. 以内に measures the length of the track.
【Example Sentences】
① レポートは来週の月曜日までに提出してください。 (レポートはらいしゅうのげつようびまでにていしゅつしてください。) → Please submit your report by next Monday. ▸ The classic deadline pattern — a fixed date + までに + submission verb
② 会議が始まるまでに、資料をコピーしておいてください。 (かいぎがはじまるまでに、しりょうをコピーしておいてください。) → Please make copies of the documents before the meeting starts. ▸ Verb + までに — the deadline is an upcoming event, not a fixed clock time
③ このクーポンは今月末までに使わないと、無効になってしまいます。 (このクーポンはこんげつまつまでにつかわないと、むこうになってしまいます。) → If you do not use this coupon by the end of the month, it will become invalid. ▸ までに embedded in a conditional — the consequence of missing the deadline is made explicit
④ 「卒業するまでに、一度でいいから教授に名前を覚えてもらいたかった」と友人が言っていた。教授のコメントは四年間ずっと「よく書けました、えーと……君」だったらしい。 (「そつぎょうするまでに、いちどでいいからきょうじゅにまえをおぼえてもらいたかった」とゆうじんがいっていた。きょうじゅのコメントはよねんかんずっと「よくかけました、えーと……きみ」だったらしい。) → My friend said, “Before graduating, I just wanted the professor to remember my name at least once.” Apparently the professor’s feedback for all four years was consistently: “Well written, uh… you.” ▸ Verb + までに expressing an aspiration with a natural deadline — and a quiet indictment of large lecture classes
【Question】
Read the following sentences and choose the grammatically correct one.
① 映画が終わるまでに、ずっとポップコーンを食べていた。 ② 映画が終わるまで、ずっとポップコーンを食べていた。 ③ 映画が終わるまでに、席に座ってください。 ④ 映画が終わるまで、席に座ってください。
Answer: ② and ③
② is correct because eating popcorn is an ongoing action that continues throughout the entire duration of the film — from beginning to end. This is precisely the usage of まで: a state or action that fills the period up to the boundary. までに here would be unnatural because the eating is not a single completed action but a continuous one.
③ is correct because taking your seat is a single, completed action that must happen before the film ends. This is the defining condition for までに: a one-time completion with a deadline. まで here would imply sitting continuously until the end, which is not the intended meaning of the instruction.
① is incorrect because ずっと (continuously, the whole time) signals an ongoing action — which requires まで, not までに.
④ is grammatically possible but carries the unintended meaning of “please remain seated until the film ends” — a continuous state, not a deadline-bound instruction. The nuance shifts entirely with the particle choice.