Business day calculator
Counts without weekends and public holidays. Choose Korea, Japan, or only days when both are open.
Business days between dates
Both the start and end dates are counted.
Holidays on weekdays
Add or subtract business days
Holiday data covers 2026-01-01 – 2027-12-31
How to use
- Choose the calendar. "Korea and Japan both open" counts only days that are business days in both.
- Read the business days between two dates, or the date N business days after or before a start date.
- Weekday holidays that were skipped are listed with their names under the result.
Questions
What counts as a business day?
Monday to Friday, except public holidays in the chosen country, including substitute holidays and election days. Company or bank closures (anniversaries, year-end breaks) are not included.
Where does the holiday data come from?
For Korea, the Regulation on Holidays of Government Offices and the official almanac (월력요항); for Japan, the Cabinet Office list of national holidays. From 2026 Korea also observes Labour Day (1 May) and Constitution Day (17 July).
Are one-off holidays included?
Yes, once the government designates them we add them. Until then the day counts as a business day.
How is "N business days after" counted?
The start date is day 0, and counting begins with the next business day. One business day after a Friday is the following Monday.
Can I calculate 2028 and later?
Not yet. Korea usually fixes the next year's holidays in June, Japan in February; we add each year as soon as it is fixed.
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