Korean Dates and Weekdays Are All Sino-Korean

The calendar does not mix

Telling time mixes the two sets in one reading. The calendar does not mix. Month, day, and weekday are all Sino-Korean.

That is the opposite of 세 시. It looks unfair until you see what a date is doing. A clock hour counts a slot, the way 한 개, 두 마리 count things you can point at. A month name, a day of the month, and a weekday are labels on a written calendar. They came in with the Chinese characters for those labels, so they sit with 일, 이, 삼 — the same set as minutes and money. The two number systems are the root. The calendar just never switches back.

Month, day, weekday

Months: 일 월 through 십이 월, usually written 1월, 12월. Two readings are fixed: 유월 for June, 시월 for October. 육월 and 십월 are the forms learners invent from 육 and 십.

Days of the month: 일 일, 이 일, 삼 일 … 삼십일 일. Speech is Sino-Korean. Writing is often 3일, 15일.

Weekdays keep the same set, with 요일 attached: 월요일, 화요일, 수요일, 목요일, 금요일, 토요일, 일요일 (woryoil, hwayoil, suyoil, mogyoil, geumyoil, toyoil, iryoil). There is no 한요일.

In a sentence

오늘은 금요일이에요.
oneureun geumyoirieyo — Today is Friday.

오늘 refuses 에. 는 sets today against other days — 은/는 vs 이/가. 금요일이에요 is 이다 after a batchim, so -이에요.

월요일에 만나요.
woryoire mannayo — Let’s meet on Monday.

The weekday takes 에 the way a clock time does. Stack the two and 에 waits for the end: 월요일 세 시에. Native hour, Sino-Korean day. Each half keeps the set it had on its own page.

몇 월 며칠이에요? asks the date. 무슨 요일이에요? asks the weekday. 주말에 가요 is the weekend, and 주말 takes 에.

Years and the test

Years are Sino-Korean too: 이천이십육 년. Age in 살 stays native — 스무 살 — because 살 counts a person the way 개 counts an apple. The year label on a calendar does not.

If a sentence has a clock in it, listen for the switch at 시. If it has only a calendar, stay on Sino-Korean all the way through. Money and 만 stay on that same set — and 만 is not an English thousand.