Date Calculator

Date difference, addition, and business day calculation with Japanese holidays.

広告スペース 1

How to use

  1. Select the calculation mode.
  2. Enter the base date and value.
  3. Choose business day options if needed.
  4. View the calculated result instantly.

About this tool

The Date Calculator handles three common calculations in one place: the difference between two dates, adding or subtracting days from a base date, and counting business days while excluding weekends and Japanese public holidays. Everything runs instantly in your browser.

Features

Three calculation modes, holiday-aware business day mode, support for years, months, and days, and clear result formatting. The holiday list is built into the tool and covers modern Japanese public holidays.

Use cases

Useful for planning project deadlines, estimating delivery dates, calculating contract durations, scheduling holidays, or figuring out how many business days remain until a given milestone at work or school.

Why this tool

Counting days by hand is slow and error prone, especially when public holidays matter. This tool combines three calculators in one interface, saving time and ensuring consistent results across your workflow.

広告スペース 2

FAQ

Does it skip Japanese holidays?
Yes, business day mode excludes weekends and Japanese public holidays automatically.
Can I calculate past dates?
Yes, you can subtract days to calculate dates in the past.
What date formats are supported?
Standard YYYY-MM-DD format is used for input and output.