Japan Business Tools
Japanese holidays, business days, eras, postal codes, addresses and corporate numbers.
| Endpoint | https://biz.ossalt.jp/mcp (streamable-http) |
|---|---|
| Registry version | 0.9.0 |
| Now | 13 tools · grade C (72) · pin ts_ce584d92d5bd3acfbf55aa4c0912ea86 · protocol 2025-06-18 |
| First / last listed | 2026-11-13 01:09 UTC / 2026-11-13 01:09 UTC |
| Grade over time | 2026-11-13: C (72), 13 tools |
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Tools: list_holidays check_business_day add_business_days count_business_days adjust_to_business_day last_business_day_of_month to_japanese_era from_japanese_era lookup_postal_code search_postal_code normalize_address lookup_corporate_number search_corporation_by_name
list_holidays | List all Japanese national holidays and substitute holidays for a year, based on the National Holidays Act and verified against the Cabinet Office CSV. Each holiday has `name` (descriptive) and `official_name` (as written by the Cabinet Office). / その年の国民の祝日・休日（振替休日・国民の休日を含む）の一覧。name は内容がわかる名前、official_name は内閣府の表記。 params: year* |
check_business_day | Check whether a date is a business day in Japan, and if not, why (weekend, holiday name, bank closure, or a custom closed day). `reason` is Japanese text; `reason_code` is one of weekend, holiday, bank_closure, extra_holiday (null on business days). flags: `estimated`/`unverified` when the year's holidays are an estimate. / その日が営業日かどうかと、休みの理由（土日・祝日の名前・銀行の休業日・指定された休日）。reason_code は weekend・holiday・ params: date*, calendar, extra_holidays, extra_business_days |
add_business_days | Return the date that is N business days after (or before, if N is negative) the given date. The start date itself is not counted; e.g. 1 business day after a Friday is the next Monday unless it is a holiday. / n営業日後（nが負なら前）の日付。起算日は数えない。 params: date*, days*, calendar, extra_holidays, extra_business_days |
count_business_days | Count business days from start to end, inclusive of both ends. Returns 0 if start is after end. The period can be up to 3,660 days (about 10 years). / start から end までの営業日の数（両端を含む）。start が end より後なら 0。期間は3,660日（約10年）まで。 params: start*, end*, calendar, extra_holidays, extra_business_days |
adjust_to_business_day | If the date is a business day, return it as is; otherwise move to the next ("next") or previous ("previous") business day. Useful for payment due dates that fall on holidays. / 営業日ならその日、休みなら次（next）または前（previous）の営業日。支払日が休みのときなどに使う。 params: date*, direction, calendar, extra_holidays, extra_business_days |
last_business_day_of_month | Return the last business day of the given month. / その月の最終営業日。 params: year*, month*, calendar, extra_holidays, extra_business_days |
to_japanese_era | Convert a Gregorian date (YYYY-MM-DD) to the Japanese era calendar, e.g. 2026-10-07 → 令和8年10月7日 (wareki_short R8.10.07, zero-padded). Year 1 is written 元年. Supported from 1873-01-01 (the Gregorian calendar was adopted on 明治6年1月1日). Eras: 令和 (R) from 2019-05-01, 平成 (H) from 1989-01-08, 昭和 (S) from 1926-12-25, 大正 (T) from 1912-07-30, 明治 (M) from 1868-01-25. flags: `assumes_current_era` for dates aft params: date* |
from_japanese_era | Convert a Japanese era date to YYYY-MM-DD. Accepts 令和8年10月7日, 令和元年5月1日, R8.10.7, H31/4/30, Reiwa 8.10.7, kanji numerals (昭和六十四年一月七日), a trailing weekday such as （水） or 水曜日, and full-width characters. `input_era`/`input_era_year` echo the input; `actual` is the correct era for that date. If the date is outside the input era (e.g. 平成31年5月1日, written after the era changed), it is still converted by c params: wareki* |
lookup_postal_code | Look up the address (prefecture, city, town) for a 7-digit Japanese postal code, from Japan Post data. Accepts forms like 1000001, 100-0001 or 〒100-0001. One code can cover several towns; all are returned. `town_detail` holds the parenthesized part as written by Japan Post (e.g. chome ranges or building floors). If the code is a business-specific code (大口事業所個別番号) or a PO box code, the business is params: postal_code* |
search_postal_code | Find Japanese postal codes by prefecture, city and (optionally) part of the town name, from Japan Post data. The city must be the full municipality name (e.g. 札幌市中央区, 新宿区); the county name may be omitted. With `office_name`, searches business-specific codes (大口事業所個別番号) of businesses in that city by name instead. Returns up to 100 matches. / 都道府県・市区町村・町域（部分一致、任意）から郵便番号を探す。市区町村は正式な名前で（郡名は省いてよい）。offi params: prefecture, city*, town, office_name |
normalize_address | Split a Japanese address into prefecture, city, town and the rest (block numbers, building), matching Japan Post's address data, and return candidate postal codes. Absorbs full/half-width, spacing, kanji vs. arabic numerals, ヶ/ケ and omitted county names; fills in the prefecture when the city is unique. Does NOT verify block/house numbers and has no coordinates. `level` tells how far the match went params: address* |
lookup_corporate_number | Look up a 13-digit Japanese corporate number (法人番号) in the National Tax Agency's monthly bulk data: name, furigana, English name, kind, registered address and postal code, assignment date, and closure (date, cause, successor) if the registry record was closed. The check digit (first digit) is verified first; a wrong check digit is reported as an input error. flags: `closed` (the registry record is params: corporate_number* |
search_corporation_by_name | Find Japanese corporations whose name starts with the given text (prefix match), in the National Tax Agency's monthly bulk data. Legal-form words such as 株式会社 or 一般社団法人 are ignored at either end, and full/half-width and spaces are normalized. Matching in the middle of a name and furigana search are not supported. flags: `truncated`, `exact_match_only` (too many names start with the input; only exa params: name*, prefecture |
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