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Business Day Calculator Tool

Count business days excluding weekends and holidays, or find the date N business days after/before in real-time. Includes Japanese national holidays with support for custom days off.

Last updated: 2026/10/16 Calculator Feedback & bug reports

* Both the start and end dates are included in the count.

One per line in YYYY-MM-DD format (e.g. 2026-08-13)

- Business Days
- Total Days
- Weekend
- Holidays / Days Off
Holidays / days off excluded in this period (0)
business days

* The start date is not counted; the next business day is counted as day 1.

One per line in YYYY-MM-DD format (e.g. 2026-08-13)

-

How to Use

1

Choose a Mode

Use the tabs to pick "Count Business Days" (between two dates) or "Date N Business Days Later" (offset from a start date).

2

Enter Dates & Options

Enter the dates, turn on "Also exclude holidays" if needed, and add any custom days off in YYYY-MM-DD format.

3

View & Copy Results

Results update in real-time as you type. Use "Copy Result" to save the output to your clipboard.

About the Business Day Calculator

A web tool that calculates the number of business days between two dates, or finds the date N business days after/before a start date, based on workdays excluding weekends and holidays. It includes Japanese national holidays (with substitute and citizens' holidays) from 1948 to 2100, and lets you add your own company days off. Ideal for managing deadlines and payment due dates.

Features

  • Two ModesCount business days or calculate a date N business days away - all in one tool.
  • Japanese Holidays Built InAutomatically excludes national, substitute, and citizens' holidays (1948–2100, including past law changes).
  • Custom Days OffAdd year-end breaks or company-specific days off in YYYY-MM-DD format.
  • Privacy ProtectedAll calculations run in your browser. Your input is never sent anywhere.

Use Cases

  • Estimating business days until delivery or acceptance
  • Calculating invoice payment due dates (within N business days)
  • Estimating bank transfer / settlement dates
  • Setting a delivery date N business days after an order
  • Tracking project working days

FAQ

What counts as a business day?
By default, business days are weekdays excluding Saturday and Sunday. Turning on "Also exclude holidays" removes Japanese holidays (including substitute and citizens' holidays). You can also add company-specific days off.
Which years of holidays are supported?
Japanese national holidays from July 20, 1948 to 2100 are built in, including the Vernal/Autumnal Equinox, substitute holidays, citizens' holidays, and moves due to law changes (such as the 2020–2021 Olympic shifts). They match the Cabinet Office list for 1955–2027; from 2028 onward they follow the current law, with equinox days as astronomical estimates. Use "Additional days off" for company-specific days off.
How are "N business days later" counted?
The start date is not counted; the next business day is day 1. For example, "1 business day after" a Friday is the following Monday (excluding weekends and holidays).
Can I exclude year-end/New Year holidays?
Yes. Since year-end breaks are not legal holidays, add the relevant dates (e.g. 2026-12-30, 2026-12-31, 2027-01-02, 2027-01-03) in the "Additional days off" field, one per line in YYYY-MM-DD format.
Is my data sent anywhere?
No. All calculations happen entirely in your browser. The dates and days off you enter are never sent to or stored on any server, so you can use it with peace of mind.

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