KoguNavi

Date Duration & Business Days Calculator

Count the days between two dates or find a business-day deadline, with weekends and Japanese national holidays handled for you.

Conversion tools

What it helps with

  • Count business days for a delivery or reply deadline
  • Check how many working days remain until a date
  • See which Japanese holidays fall inside a period

How to use

  1. Choose duration mode for two dates, or deadline mode for a start date plus business days.
  2. Pick dates with the calendar or type them as YYYY-MM-DD.
  3. Review calendar days, business days, and the Japanese holidays inside the range.

Examples

One week

Input

2026-07-06 | 2026-07-12

Output

Business days: 5

Range with a holiday

Input

2026-07-13 | 2026-07-26

Output

Business days: 9 (Marine Day skipped)

Deadline after 5 business days

Input

2026-07-16 + 5 business days

Output

2026-07-24

Good to know

  • Holidays follow the current national holiday rules from 2020 onward, including the 2020/2021 Tokyo Olympics moves; older years are not covered.
  • Company-specific closures such as year-end breaks or Obon are not included.
  • Supported years are 2020-2099.

FAQ

Which holidays are excluded from business days?
Japanese national holidays under the current rules, including substitute holidays and citizens' holidays, for the years 2020-2099.
Is the start date counted?
Duration mode shows both inclusive and exclusive day counts. Deadline mode starts counting from the next day, which matches common Japanese business usage.
Are dates uploaded?
No. All calculations run in your browser.

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