Korean public holidays, substitute holidays, and counting business days

1. What sets the public holidays

The days public offices close are set by a presidential decree, the Regulations on Public Holidays for Public Offices. Article 2 lists eleven items: Sundays, the national days, 1 January, the Seollal holiday, Buddha's Birthday, Labor Day, Children's Day, Memorial Day, the Chuseok holiday, Christmas, and election and temporary holidays. The national days are set by the Act on National Holidays: Independence Movement Day, Constitution Day, Liberation Day, National Foundation Day and Hangeul Day.

Two things changed in 2026. Labor Day (1 May) became a holiday from 1 May, and Constitution Day, dropped in 2008, became a holiday again from 11 May. The Act on Public Holidays was amended first and the decree followed. So dates before May 2026 must be counted under the old rule and dates after it under the new one. This page decides which version applies to each date on its own.

Employees also look to Article 55(2) of the Labor Standards Act. Since 2022, workplaces with five or more employees have the public and substitute holidays as paid days off. Workplaces with fewer than five, or those with a written labor agreement, may differ.

2. The three cases that create a substitute holiday

The substitute holiday is set by Article 3 of the regulation. When a holiday overlaps and a day off is lost, the first non-holiday after it is taken instead, and paragraph 1 splits this into three cases. First, when the national days, Buddha's Birthday, Labor Day, Children's Day or Christmas fall on a Saturday or Sunday. Second, when the Seollal or Chuseok holiday falls on a Sunday. These two get no substitute if they fall on a Saturday. Third, when any of these meet another holiday on a weekday.

1 January and Memorial Day are in no such item, so they get no substitute even on a weekend. The same is true of election and temporary holidays. This is because the regulation names its target holidays by item number.

The rule for placing the substitute day has two exceptions. If two substitute days would fall on the same date, the days off extend to the next non-holiday after that (paragraph 2), and if the substitute day is itself a Saturday it moves to the next non-holiday (paragraph 3). So in a year with a long overlap the substitute days chain one after another.

3. How this app computes

This app does not hand-write the holidays; it computes Article 2 directly. Dates fixed on the solar calendar stay as they are, and Seollal (lunar 1 January), Buddha's Birthday (lunar 4 August) and Chuseok (lunar 8 August 15) are converted from the lunar calendar. The conversion table is a public library on the astronomy institute's standard, bundled into the app, and its values were checked against the institute's own conversion page.

Then Article 3 is applied to build the substitute holidays. It finds the day lost to an overlap and takes the first non-holiday after it, skipping Sundays and days already holidays, and moving on once more if the result is a Saturday or already taken.

Temporary holidays and fixed-term election days do not follow from the rule. A temporary holiday is fixed only after the government passes it in a State Council meeting and gazettes it, and an election day is announced by the election commission. So these two are kept in a separate table, each with its source and check date, and unconfirmed days are left out. The computed holidays are also published as a single file so other apps can use them directly.

Next to each substitute holiday on screen is its source clause, showing which item of Article 3(1) created it and what it stands in for, with the clause openable in the national law database.

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4. Counting a deadline in business days

Contracts and filing notices often set a deadline in business days, which are the days left after removing Saturdays, Sundays and public holidays. This calculator does two things: it counts what date is N business days from a start date, and how many business days lie between two dates.

Article 157 of the Civil Act says the first day of a period is not counted. File today with a seven-business-day deadline and today is excluded, counting from tomorrow. So the calculator excludes the start day by default, and you can turn that off when a form counts the first day. Article 161 adds that when a period's last day is a Saturday or a holiday, it ends on the next day.

Whether a given deadline is counted in calendar days or business days, and whether the first day is included, can be set by the specific law or contract. This calculator follows the ordinary rule, but a notice that says otherwise governs.

• 민법 제157조: 제157조(기간의 기산점) 기간을 일, 주, 월 또는 연으로 정한 때에는 기간의 초일은 산입하지 아니한다. 그러나 그 기간이 오전 영시로부터 시작하는 때에는 그러하지 아니하다.
• 민법 제159조: 제159조(기간의 만료점) 기간을 일, 주, 월 또는 연으로 정한 때에는 기간말일의 종료로 기간이 만료한다.
• 민법 제161조: 제161조(공휴일 등과 기간의 만료점) 기간의 말일이 토요일 또는 공휴일에 해당한 때에는 기간은 그 익일로 만료한다.

5. Where people get confused

Constitution Day is a national day but was not a public holiday from 2008 through 2025. It became one again from 11 May 2026, so 17 July being an ordinary day on a calendar up to 2025 is not a mistake.

When the Seollal or Chuseok holiday overlaps a Saturday, no substitute holiday appears, because the regulation substitutes these two only for a Sunday overlap. Children's Day on a Saturday, by contrast, does get one. That is why the same weekend can give different results.

Only fixed-term elections are the holiday the regulation names. An election held because a term ended early, such as a presidential vacancy election, is instead designated a temporary holiday by the government each time. The presidential election of 3 June 2025 was such a case and appears in this app's temporary-holiday table.

This app counts holidays for 2026 through 2030. Enter another year in the business-day calculator and it will not compute; it says there is no data, because counting silently without holidays would put a deadline off by a day.

The clauses, verbatim (Korean)

관공서의 공휴일에 관한 규정. Presidential Decree No. 36290, promulgated 2026-04-30, in force 2026-05-01. Checked 2026-09-06.