Overview
This lesson covers the vocabulary and patterns for talking about when things happen: relative time words (today, yesterday), the days of the week, the months of the year, and the dates of the month. Most of this is straightforward memorization, but several readings are irregular and must be learned individually — those are flagged with ⚠️ throughout.
Part 1: Relative Time Words
| Japanese | Romaji | English |
| きょう | kyou | today |
| きのう | kinou | yesterday |
| あした | ashita | tomorrow |
| あさって | asatte | the day after tomorrow |
| おととい | ototoi | the day before yesterday |
| まいにち | mainichi | every day |
💡 No に with these words. Relative time words already point to a moment in time on their own, so they do not take the particle に.
- ✅ きょう いきます。 (I’m going today.)
- ❌ きょうに いきます。
This is different from specific time expressions — a clock time, a named day, a date, or a month — which do take に (covered below). The rule of thumb: if the word’s meaning shifts depending on when you say it (today, tomorrow), no に; if it names a fixed point (Monday, May, the 3rd), use に.
Part 2: Days of the Week (曜日)
Asking and Answering
きょうは なんようびですか？ → What day of the week is it today? きょうは ＿＿＿です。 → Today is ___.
なん means “what,” so なんようび literally asks “what day-of-the-week.”
The Days
| Japanese | Romaji | Day | Element kanji |
| げつようび | getsuyoubi | Monday | 月 (moon) |
| かようび | kayoubi | Tuesday | 火 (fire) |
| すいようび | suiyoubi | Wednesday | 水 (water) |
| もくようび | mokuyoubi | Thursday | 木 (wood) |
| きんようび | kin’youbi | Friday | 金 (gold / metal) |
| どようび | doyoubi | Saturday | 土 (earth) |
| にちようび | nichiyoubi | Sunday | 日 (sun) |
💡 Why ようび? The word 曜日 (ようび) itself means “day of the week.” Every day is built the same way: [element] + ようび. So once you know the seven element kanji, you know all seven days.
💡 Memory tip — the Seven Luminaries. The elements aren’t random. They come from a classical seven-day astronomy system shared across Eurasia: Moon, Mars (fire), Mercury (water), Jupiter (wood), Venus (gold), Saturn (earth), and Sun. This is the same logic behind the European names — Monday/Lundi (moon), Saturday/Saturn, Sunday/Sun — which can make the set easier to anchor if you already know a Romance language.
Practice Pattern
わたしは ＿＿＿ようびが すきです。 → I like ___days.
(e.g. どようびが すきです — I like Saturdays.)
Part 3: Months (〜月)
Asking and Answering
こんげつは なんがつですか？ → What month is it? ＿＿＿がつです。 → It is ___.
Months are formed with [number] + がつ. The pattern is mostly regular — but ⚠️ three months use irregular number readings. These are the single most common pronunciation mistake beginners make, so learn them deliberately.
| Month | Japanese | Romaji | Note |
| January | 1がつ | ichigatsu | |
| February | 2がつ | nigatsu | |
| March | 3がつ | sangatsu | |
| April | 4がつ | shigatsu | ⚠️ し, not よん |
| May | 5がつ | gogatsu | |
| June | 6がつ | rokugatsu | |
| July | 7がつ | shichigatsu | ⚠️ しち, not なな |
| August | 8がつ | hachigatsu | |
| September | 9がつ | kugatsu | ⚠️ く, not きゅう |
| October | 10がつ | juugatsu | |
| November | 11がつ | juuichigatsu | |
| December | 12がつ | juunigatsu |
💡 The trap in detail. The numbers 4, 7, and 9 each have two readings in Japanese — a native reading (よん / なな / きゅう) and a Sino-Japanese reading (し / しち / く). For months, only the Sino-Japanese reading is correct. Saying よんがつ or きゅうがつ will be understood but immediately marks you as a beginner, so it’s worth drilling these three until they’re automatic.
Part 4: Dates (〜日)
Asking and Answering
きょうは なんにちですか？ → What’s the date today? きょうは なんがつ なんにちですか？ → What’s today’s date? (month + day)
The 1st–10th — Special Native Readings
The first ten days do not use the number-plus-にち pattern. They use older native Japanese readings and must be memorized individually.
| Date | Japanese | Romaji | Date | Japanese | Romaji |
| 1st | ついたち | tsuitachi | 6th | むいか | muika |
| 2nd | ふつか | futsuka | 7th | なのか | nanoka |
| 3rd | みっか | mikka | 8th | ようか | youka |
| 4th | よっか | yokka | 9th | ここのか | kokonoka |
| 5th | いつか | itsuka | 10th | とおか | tooka |
💡 A hook for the 2nd–10th. These nine readings echo Japan’s native counting set (ひとつ、ふたつ、みっつ…). Listen for the overlap: ふつか ↔ ふたつ (2), みっか ↔ みっつ (3), よっか ↔ よっつ (4), いつか ↔ いつつ (5). The 1st (ついたち) is the odd one out — it comes from 月立ち tsuki-tachi, “the moon’s rising,” i.e. the start of the lunar month.
From the 11th — The Regular Pattern (with three traps)
From the 11th on, dates are regular: [number] + にち.
| Date | Japanese | Romaji | Date | Japanese | Romaji |
| 11th | じゅういちにち | juuichinichi | 21st | にじゅういちにち | nijuuichinichi |
| 12th | じゅうににち | juuninichi | 22nd | にじゅうににち | nijuuninichi |
| 13th | じゅうさんにち | juusannichi | 23rd | にじゅうさんにち | nijuusannichi |
| 14th | じゅうよっか | juuyokka ⚠️ | 24th | にじゅうよっか | nijuuyokka ⚠️ |
| 15th | じゅうごにち | juugonichi | 25th | にじゅうごにち | nijuugonichi |
| 16th | じゅうろくにち | juurokunichi | 26th | にじゅうろくにち | nijuurokunichi |
| 17th | じゅうしちにち | juushichinichi | 27th | にじゅうしちにち | nijuushichinichi |
| 18th | じゅうはちにち | juuhachinichi | 28th | にじゅうはちにち | nijuuhachinichi |
| 19th | じゅうくにち | juukunichi | 29th | にじゅうくにち | nijuukunichi |
| 20th | はつか | hatsuka ⚠️ | 30th | さんじゅうにち | sanjuunichi |
| 31st | さんじゅういちにち | sanjuuichinichi |
⚠️ The three irregularities to memorize:
- Any date ending in 4 keeps the よっか reading from the 4th: 14th = じゅうよっか, 24th = にじゅうよっか.
- The 20th is completely irregular: はつか — not “にじゅうにち.” (It shares the は- sound with はたち, the word for “20 years old.”)
- The 7s and 9s use Sino-Japanese readings: 17th = じゅうしちにち, 19th = じゅうくにち (and likewise 27th, 29th) — the same し / しち / く readings you met in the months. Saying なな or きゅう here sounds off.
Vocabulary & Practice
たんじょうび = birthday
わたしの おとうとの たんじょうびは ＿＿＿です。 → My younger brother’s birthday is ___.
(e.g. しがつ ようかです — April 8th.)
💡 Word order for full dates. Japanese always goes larger unit → smaller unit: year → month → day. So “April 8th” is しがつ ようか (month first, then day), the reverse of the American “April 8” being said but the same as writing 4/8.
Summary
| Category | Pattern | Watch out for |
| Relative time words | memorize | no に particle |
| Days of the week | [element] + ようび | none — fully regular |
| Months | [number] + がつ | ⚠️ 4 し / 7 しち / 9 く |
| Dates 1–10 | special native readings | all must be memorized |
| Dates 11+ | [number] + にち | ⚠️ -4 → よっか, 20 → はつか, 7s/9s → しち/く |