Korean Holiday & Business-Day CLI

Zero-config CLI for Korean public holidays, business-day math, and Korean lunar↔solar conversion. No API key. No network required at runtime.

• Public holidays powered by the holidays package (Korean names, substitute holidays / 대체공휴일 included).
• Lunar↔solar powered by korean-lunar-calendar (KASI astronomical tables, supports 윤달).

When to use

Trigger this skill for any of:

• Is a given date a Korean public holiday? ("2026-05-05 공휴일이야?")
• List Korean holidays for a year or month
• Compute next/previous business day, skipping weekends AND Korean holidays
• Add a signed business-day offset (e.g., invoice due in +10 business days from order date)
• Count business days between two dates (payroll, SLA, delivery ETA)
• Convert solar ↔ Korean lunar dates (음력 생일 lookup, 설날·추석 date lookup)
• Render a monthly calendar view with holidays marked

Do not use for:

• Regional / religious holidays that aren't recognized as national public holidays (예: 성탄절 제외 종교 행사)
• Company-specific working calendars (add your own per-company overrides outside this skill)
• Realtime election-day announcements (bundled rules reflect statutory holidays; ad-hoc presidential decree holidays may lag until the holidays package updates)

Install

pip install -r scripts/requirements.txt

Dependencies: holidays, korean-lunar-calendar.

Usage

All commands are sub-commands of scripts/kr_holiday.py. Output is JSON (UTF-8, Korean preserved). Dates accept YYYY-MM-DD, YYYYMMDD, YYYY/MM/DD, or YYYY.MM.DD.

Check a date

python scripts/kr_holiday.py is-holiday 2026-05-05
# → {"date":"2026-05-05","weekday":"Tue","is_weekend":false,"is_holiday":true,"is_business_day":false,"names":["어린이날"]}

List holidays in a year (optionally filter by month)

python scripts/kr_holiday.py list --year 2026
python scripts/kr_holiday.py list --year 2026 --month 5

Next / previous business day

python scripts/kr_holiday.py next-business-day 2026-05-02                 # skip Sat → 2026-05-04 (Mon)
python scripts/kr_holiday.py next-business-day 2026-05-02 --offset 3      # 3rd next business day
python scripts/kr_holiday.py prev-business-day 2026-05-06 --offset 2

Add a signed business-day offset

python scripts/kr_holiday.py add-business-days 2026-04-20 --days 10       # 2026-05-04
python scripts/kr_holiday.py add-business-days 2026-05-05 --days -3

Count business days in a range (inclusive)

python scripts/kr_holiday.py business-days --start 2026-05-01 --end 2026-05-31
# → {"start":"2026-05-01","end":"2026-05-31","calendar_days":31,"business_days":19}

Solar ↔ Korean lunar

python scripts/kr_holiday.py solar-to-lunar 2026-02-17
# → {"solar":"2026-02-17","lunar":"2026-01-01","is_leap_month":false,"gapja":"병오년 경인월 임술일"}

python scripts/kr_holiday.py lunar-to-solar 2026-08-15
python scripts/kr_holiday.py lunar-to-solar 2025-06-01 --leap              # pass --leap for 윤달

Monthly calendar view

python scripts/kr_holiday.py month 2026 5                   # human-readable, Sunday-first
python scripts/kr_holiday.py month 2026 5 --format json     # weeks grid in JSON

Output conventions

• JSON by default (no pretty-print; pipe through python -m json.tool if desired).
• is_business_day = true ⇔ Mon–Fri AND not a Korean public holiday.
• names is a list — a single calendar day can carry multiple labels (e.g., when holidays overlap).
• Substitute holidays (대체공휴일) appear as their own entries in list output.

Error handling

• Unparseable date → exit 2, stderr JSON {"error":"bad_date","input":"…"}.
• Out-of-range month, negative offset, conversion failure → exit 2 or 3, stderr JSON.
• Missing dependency → exit 4, stderr JSON with install hint.

Notes on holiday accuracy

• 대체공휴일 rules: reflects the revised 2021/2023 rules (substitute applies when a national holiday falls on Sat/Sun, with the documented exceptions). Results match rulings published by 공공데이터포털 한국천문연구원 특일 정보 through 2030.
• Lunar holidays (설날, 추석, 부처님오신날) are computed from the lunar calendar bundled in the holidays package.
• Update holidays periodically to pick up legislative changes: pip install -U holidays.

See also

• krx-stock-cli — KRX stock market data (KOSPI/KOSDAQ)
• toss-payments-cli — Toss Payments API
• kakao-local-cli — Kakao Local place & geocoding API

License

MIT.