Business Day Calc – Japan

"What date is 5 business days from today?" "How many working days until the deadline?" — instant answers that respect Japanese public holidays, substitute holidays, and year-end breaks. Works completely offline.

■ Add / subtract business days
Count forward or backward from any date. Toggle whether the start date counts as day one — both Japanese business conventions are supported.

■ Count business days in a period
Count working days between two dates, with inclusive/exclusive endpoints.

■ Payment terms calculator (Pro)
Presets like "end-of-month closing, paid end of next month," plus fully custom closing day, payment month, and payment day. Automatic shift to the next or previous business day when payday falls on a holiday.

■ Custom working days (Pro)
Companies that work Saturdays or public holidays are supported. Register your own company holidays such as summer breaks.

■ Built-in holiday calendars: Japan, China, US
Japan: Cabinet Office data (2020–2027, incl. substitute holidays). China: State Council notices (2020–2026, incl. shifted working weekends). US: federal holidays (2020–2027, incl. observed dates). Auto-selected by app language, or pin any calendar manually (e.g. English UI with Japanese holidays). Accurate even offline.

■ Home screen widget (Pro)
Always see "5 business days from today" at a glance (Android).

■ Pro (one-time purchase, not a subscription)
Payment terms calculator, custom working days, company holidays, home widget, and no ads even if ads are added in the future.

■ Official sources (government websites)
Holiday data is based on the following official government publications:
- Japan, national holidays (Cabinet Office): https://www8.cao.go.jp/chosei/shukujitsu/gaiyou.html
- China, State Council holiday notices (gov.cn, e.g. 2026): https://www.gov.cn/zhengce/content/202511/content_7047090.htm
- US, Federal Holidays (OPM): https://www.opm.gov/policy-data-oversight/pay-leave/federal-holidays/

■ Disclaimer
This app is NOT an official app of any government agency, and is not affiliated with or endorsed by any government body. The app UI supports Japanese, English, and Simplified Chinese. Holiday data: Japan 2020–2027, China 2020–2026, US 2020–2027, per the sources above. Please verify actual trading terms and bank business days yourself.