How do Korean public holidays affect IP deadlines from 2026?

Sangwook Je, Partner · Published 6 November 2026

Last verified 9 October 2026

What changed

Two statutes set the public holidays. They are the Act on Public Holidays and the Regulations on Public Holidays of Government Offices (관공서의 공휴일에 관한 규정). [1][2] “Previous” in the table below is the text of the version immediately before the amendment. [1][2]

The national holidays under Article 2 of the Act on National Holidays are Independence Movement Day, Constitution Day (17 July), National Liberation Day, National Foundation Day and Hangul Proclamation Day. [4] So when “Independence Movement Day, National Liberation Day, National Foundation Day and Hangul Proclamation Day, among national holidays” becomes “national holidays”, Constitution Day comes in. [1][4]

The results that reach IP deadlines are as follows.

A substitute public holiday is a day set by Article 3 of the Act on Public Holidays and Article 3 of the Regulations on Public Holidays of Government Offices. [1][2] No provision states whether a substitute public holiday is a “public holiday” under Article 14, subparagraph 4 of the Patent Act or Article 161 of the Civil Act. [1][2][3][5] No Supreme Court decision and no document of the Ministry of Intellectual Property (MOIP, 지식재산처) that so decided was found either. What the provisions set is in the “Substitute public holidays” section below.

IP statutes move the end of a period when the last day is a public holiday

In a patent-related procedure, if the last day of a period is a public holiday, the period expires on the following day (Patent Act, Art. 14, subparagraph 4). [3] This public holiday includes Workers’ Day under the Act on the Designation of Workers’ Day (노동절 제정에 관한 법률) and Saturdays. [3]

The provisions of the other Acts have the same form.

The basis is the provisions of each Act in force. [3][4] The wording of the three provisions changed once, on 11 November 2025. Article 2 of the Addenda to the Act on the Designation of Workers’ Day (Act No. 21134) replaced the name Workers’ Day (근로자의 날) with Workers’ Day (노동절). [3][4] What changed is the name. 1 May was stated in the three provisions before that as well. [3][4]

The provisions above do not state separately which days are “public holidays”. [3][4] Article 3 of the Addenda to the Act on Public Holidays (Act No. 18291) connects the two. Public holidays used in other statutes at the time this Act enters into force are deemed to include the public holidays under this Act and Sundays. [1] The exception is where it is clear that Sundays are not included. [1] The enforcement date of this Act is 1 January 2022. [1]

As of 9 October 2026, the public holidays under Article 2 of the Act on Public Holidays are as follows. [1]

• National holidays under the Act on National Holidays
• 1 January
• The day preceding Seollal, Seollal and the day following Seollal (the last day of December, and 1 and 2 January in the lunar calendar)
• Buddha’s Birthday (8 April in the lunar calendar)
• Workers’ Day (1 May)
• Children’s Day (5 May)
• Memorial Day (6 June)
• The day preceding Chuseok, Chuseok and the day following Chuseok (14, 15 and 16 August in the lunar calendar)
• Christmas Day (25 December)
• Election days for elections upon the termination of terms of office under Article 34 of the Public Official Election Act (공직선거법)
• Other days designated occasionally by the Government

The other rules for the calculation of periods are in “What are the key deadlines in Korean patent practice?“.

Workers’ Day: periods for patent procedures do not change

Workers’ Day became a public holiday on 1 May 2026. The Act on Public Holidays (Act No. 21543) was promulgated on 9 April 2026 and entered into force on 1 May 2026. [1]

Periods for patent-related procedures do not change with this amendment. The reason is that Article 14, subparagraph 4 of the Patent Act already stated 1 May separately. [3] The same applies to Article 16, subparagraph 4 of the Trademark Act and Article 16, subparagraph 4 of the Design Protection Act. [4]

Two things changed.

First, Workers’ Day now has a substitute public holiday. Workers’ Day (Art. 2, subparagraph 6) was added to the public holidays covered by Article 3(1), subparagraph 1 of the Regulations on Public Holidays of Government Offices. [2] If Workers’ Day overlaps with a Saturday or Sunday, the first non-public holiday following it is the substitute public holiday. [2]

Second, periods to which Article 161 of the Civil Act applies. Article 161 of the Civil Act states only “a Saturday or a public holiday” and does not state Workers’ Day separately. [5] This is described in the “Revocation actions” section below.

The statement of reasons for the amendment carried by the Ministry of Government Legislation (법제처) said that Workers’ Day had been a holiday that applied only to private-sector workers. [1] The Act on the Designation of Workers’ Day makes 1 May a paid holiday under the Labor Standards Act (근로기준법). [4]

Constitution Day: a public holiday from 11 May 2026

Constitution Day (17 July) is a public holiday from 11 May 2026. The Act on Public Holidays (Act No. 21338) was promulgated on 10 February 2026. [1] The Addenda provide that the Act enters into force 3 months after the date of its promulgation. [1]

The national holidays in the previous Article 2, subparagraph 1 were four: Independence Movement Day, National Liberation Day, National Foundation Day and Hangul Proclamation Day. [1] The amended Article 2, subparagraph 1 covers all national holidays under the Act on National Holidays. [1] Constitution Day is a national holiday under Article 2, subparagraph 2 of that Act. [4]

The first Constitution Day after enforcement was Friday, 17 July 2026. In a patent-related procedure, if the last day of a period is 17 July, the period expires on the following day (Patent Act, Art. 14, subparagraph 4). [1][3] The same applies to trademark and design procedures and to utility model procedures. [4]

Constitution Day is also covered by the substitute public holiday rule. Constitution Day is a national holiday under Article 2, subparagraph 2 of the Regulations on Public Holidays of Government Offices, and subparagraph 2 is stated in Article 3(1), subparagraph 1. [2]

Substitute public holidays: 3 May and 19 July in 2027

Substitute public holidays are set by Article 3 of the Regulations on Public Holidays of Government Offices. Article 3 of the Act on Public Holidays left their designation and operation to Presidential Decree. [1][2]

The substitute public holiday is the first non-public holiday following that public holiday. [2] A non-public holiday is a day that is not a public holiday under the subparagraphs of Article 2 of the same Regulations. [2] If the substitute public holiday is a Saturday, the first non-public holiday after it is the substitute public holiday (Art. 3(3)). [2] If substitute public holidays overlap on the same day, the days up to and including the first non-public holiday after that substitute public holiday are substitute public holidays (Art. 3(2)). [2] 1 January (Art. 2, subparagraph 3) and Memorial Day (Art. 2, subparagraph 8) are not stated in the subparagraphs of Article 3(1). [2] Election days and days designated occasionally by the Government are not covered by Article 3(1) either. [2]

In 2027, Workers’ Day and Constitution Day are both Saturdays. [8] The press release on the Calendar Summary for 2027 (2027년 월력요항), announced by the Korea AeroSpace Administration (KASA, 우주항공청) on 29 June 2026, stated the following. [8]

Does a substitute public holiday move the last day of a period?

The provisions alone do not settle it. What the sources state is as follows.

• The Act on Public Holidays states “public holidays under Article 2” and “substitute public holidays under Article 3” separately (Art. 4). [1]
• Article 3 of the Addenda to the same Act (Act No. 18291) deems public holidays in other statutes to include “the public holidays under this Act” and Sundays. [1]
• The Supreme Court of Korea decided whether the last day of a period was a public holiday by the subparagraphs of Article 2 of the Regulations on Public Holidays of Government Offices (Supreme Court Order 2020Mo3694 Dated January 14, 2021). [9] That order concerns a period under the Criminal Procedure Act (형사소송법) and a temporary public holiday. [9] It did not deal with substitute public holidays. [9]
• A substitute public holiday is a day set by Article 3 of the same Regulations, not by Article 2. [2]
• The press release on the Calendar Summary for 2027 counted substitute public holidays in the number of “public holidays of government offices”. [8]
• The Patent Examination Guidelines (특허·실용신안 심사기준) (MOIP Established Rule No. 7) contain no sentence that states substitute public holidays. [7]

No Supreme Court decision was found that held a substitute public holiday to be a public holiday under Article 14, subparagraph 4 of the Patent Act or Article 161 of the Civil Act. So this article does not conclude either way. The table in the example below gives the expiration dates for both cases.

Revocation actions: Article 161 of the Civil Act applies

Article 14, subparagraph 4 of the Patent Act does not apply to the period for filing a revocation action. The Supreme Court held that Article 161 of the Civil Act applies to that calculation (Supreme Court Decision 2013Hu1573 Decided February 13, 2014). [6] The route the decision gave is Article 170 of the Civil Procedure Act (민사소송법), which applies mutatis mutandis under Article 8 of the Administrative Litigation Act (행정소송법). [6] Article 170 of the Civil Procedure Act provides that the calculation of periods is governed by the Civil Act. [5]

A revocation action must be filed within 30 days from the date on which the certified copy of the trial decision is served (Patent Act, Art. 186(3)). [3] This period is an invariable period (paragraph (4) of the same Article). [3] The decision above found that “patent-related procedures” do not include the procedure for a revocation action. [6] The decision stated that the same legal principle applies to utility models. [6]

The Acts that the decision above applied are the Patent Act and the Utility Model Act before the amendment of 3 March 2006. [6] Article 14, subparagraph 4 of the Patent Act in force also states only periods for “patent-related procedures”. [3] Article 5 in force also states patent-related procedures and the filing of an action against a disposition of an administrative authority separately. [3] Article 162 of the Trademark Act and Article 166 of the Design Protection Act also set an invariable period of 30 days. [4] The decision above did not deal with revocation actions for trademarks and designs. [6]

In that case, the 30th day was Wednesday, 1 May 2013. [6] The complaint was filed on the following day. [6] The Supreme Court found that Workers’ Day (근로자의 날) does not fall under “a Saturday or a public holiday” in Article 161 of the Civil Act. [6] The action was held to have been filed after the period for filing the action had passed. [6]

The wording of Article 161 of the Civil Act has not changed since then. Where the last day of a period falls on a Saturday or a public holiday, the period expires on the following day. [5] What changed is the list of public holidays. Workers’ Day is a public holiday under Article 2, subparagraph 5 of the Act on Public Holidays from 1 May 2026. [1]

Workers’ Day on or after 1 May 2026 is a public holiday under Article 161 of the Civil Act. There are three grounds.

• Workers’ Day is a public holiday under Article 2, subparagraph 5 of the Act on Public Holidays. [1] Article 3 of the Addenda to the same Act (Act No. 18291) deems public holidays in other statutes to include the public holidays under this Act. [1]
• Workers’ Day is a public holiday under Article 2, subparagraph 6 of the Regulations on Public Holidays of Government Offices. [2] Article 2 of the previous version (Presidential Decree No. 33448) did not have 1 May. [2]
• The Supreme Court decided what is a public holiday under Article 161 of the Civil Act by the subparagraphs of Article 2 of the same Regulations (Supreme Court Order 2006Ma851 Dated June 12, 2008). [9] That order found that a non-working Saturday does not fall under any of the subparagraphs of Article 2. [9]

Decision 2013Hu1573 is a ruling about the day 1 May 2013, and it was rendered before the Act on Public Holidays was enacted. [1][6] No Supreme Court decision was found that deals directly with Workers’ Day after the amendment.

Where an additional period is set

The presiding administrative patent judge can set an additional period ex officio for a person whose domicile or residence is in a remote area or in an area with poor access to transport (Patent Act, Art. 186(5)). [3] The Intellectual Property High Court of Korea (Patent Court of Korea, 특허법원) found that the additional period forms one body with the 30-day period for filing the action (Patent Court Decision 2023Heo11791 Decided January 10, 2024). [10] In that case, the period for filing the action was calculated as 50 days, the 30 days plus an additional period of 20 days. [10] The 30th day was a public holiday, but the period was not separately moved from that day. [10] This is a judgment of the IP High Court of Korea. Whether a final appeal was filed and whether the judgment became final and conclusive could not be confirmed.

The other details of the period for filing the action are in “How are trial decisions appealed to the Intellectual Property High Court of Korea (Patent Court of Korea)?”.

What a public holiday does not change

What moves to the following day is the statutory periods and designated periods (specified period) for patent-related procedures. Chapter 3 of Part 1 of the Patent Examination Guidelines states the following three points. [7]

• A period that is not for a patent-related procedure is not subject to Article 14, subparagraph 4 of the Patent Act. As examples, the Guidelines give the time at which the earlier application is deemed withdrawn under a domestic priority claim, and the expiration date of the term of the patent. [7]
• Even if the start date of a period is a public holiday, the period begins from that public holiday. [7]
• Where a period is extended under Article 15 of the Patent Act, the original period expires on the public holiday even if its last day is a public holiday. The extended period is counted from the day after the day on which the designated period expired. [7]

The Article 14, subparagraph 4 of the Patent Act that Chapter 3 of Part 1 of the Guidelines reproduces is the old wording, with Workers’ Day (근로자의 날). [7] The wording of the Patent Act in force is Workers’ Day (노동절). [3] This article follows the Act.

The period within which an application with a priority claim under the Treaty can be filed does move for a public holiday. Chapter 3 of Part 6 of the Guidelines states that this period is calculated in the same way as under Article 14 of the Patent Act. [7] It states that if the last day is a public holiday, the application can be filed by the following day. [7]

The calculation of extensions of periods is in “How much do extensions of time cost at the Korean patent office?“.

Cases that straddle the enforcement date

The Addenda to the two amending Acts contain only the enforcement date. The Addenda to Act No. 21543 read “This Act shall enter into force on 1 May 2026.” [1] The Addenda to Act No. 21338 read “This Act shall enter into force 3 months after the date of its promulgation.” [1] There is no applicability provision and no transitional measure. [1]

The Addenda to the Regulations on Public Holidays of Government Offices (Presidential Decree No. 36290) also set only the enforcement date. The Decree enters into force on 1 May 2026, and the amended provisions of the proviso to Article 2 and of subparagraph 2 of that Article enter into force on 11 May 2026. [2]

No provision deals separately with the case where the last day of a period that began before enforcement is a new public holiday. [1][2] Article 14, subparagraph 4 of the Patent Act asks only whether the last day of the period is a public holiday. [3] The provision makes no distinction by when the period began. [3] 17 July 2026 is a public holiday under Article 2, subparagraph 1 of the Act on Public Holidays in force on that day. [1] So a period that began before 11 May 2026 also falls within the wording of Article 14, subparagraph 4 if its last day is 17 July 2026. [1][3]

Example: four cases in which the last day is a new public holiday

The cases below are assumed. The days of the week and the substitute public holidays in 2027 follow the press release on the Calendar Summary for 2027. [8]

The fourth row is a case in which the certified copy of the trial decision was served on 1 April 2026. Counting without the first day, the 30th day is 1 May 2026 (Patent Act, Art. 14, subparagraph 1; Civil Act, Art. 157). [3][5] 1 May 2026 is a public holiday under Article 161 of the Civil Act, as described in the “Revocation actions” section above. [1][2][9]

The second and third rows differ by one day depending on whether a substitute public holiday is a public holiday. No provision or court decision that settles this was found.

If the following day is also a public holiday, the period moves again to the day after that. The Guidelines give as an example a case in which the last day is in the Seollal holidays and the following day is a Sunday. That period expires on the day after the Sunday. [7] On Article 161 of the Civil Act, the Supreme Court stated that if the last day of a period is a Saturday, the period expires on the Monday (Order 2006Ma851). [9]

Counting under the previous provisions gives different results. 17 July in the first row was not a public holiday under the previous Article 2. [1] The Mondays in the second and third rows were not substitute public holidays under the previous Regulations. [2] 1 May in the fourth row was a day that was not in the previous Article 2. [1]

The press release on the Calendar Summary for 2027 stated 1 to 3 May and 17 to 19 July each as a 3-day holiday period. [8] The two expiration dates in 2026 (4 May and 20 July) are not public holidays that Article 2 sets by a date in the solar calendar. [1] Public holidays set by the lunar calendar and days designated occasionally by the Government are not reflected in this table.

What is not yet settled

The basis is the statutes, the Guidelines and the press release above. [1][2][7][8] As of 9 October 2026, the Ministry of Government Legislation shows no version scheduled to enter into force for the Act on Public Holidays or the Regulations on Public Holidays of Government Offices. [1][2] Article 14, subparagraph 4 of the amended Patent Act that enters into force on 16 March 2027 (Act No. 21955) is the same as the provision in force. [3] Article 3 of the Utility Model Act (Act No. 21953) and Article 16 of the Design Protection Act (Act No. 21951), which enter into force on the same day, are also the same as the provisions in force. [4] Article 170 of the Civil Procedure Act and Article 8 of the Administrative Litigation Act that enter into force on 1 March 2028 are also the same as the provisions in force. [5]

What applicants should do

• In general, we suggest checking that the calendar used to manage Korean deadlines contains 17 July and the two substitute public holidays. A calendar made before May 2026 may not have them.
• We suggest giving instructions on the basis of the last day before the period moves for a public holiday, without relying on the days added by a public holiday. Temporary public holidays cannot be known in advance, and there is no statement by the authorities on substitute public holidays.
• We suggest counting the period for filing a revocation action separately from the periods for patent procedures. The provision that applies is Article 161 of the Civil Act.
• We suggest marking separately in the calendar the days that do not move for a public holiday, such as the expiration date of the term of the patent.
• We suggest planning the schedule on the premise that public holidays in the applicant’s country are not reflected in Korean periods. The list in Article 2 of the Act on Public Holidays contains only Korean public holidays.

Please confirm the deadlines of an individual case with your agent.

FAQ

Which days newly became public holidays in Korea in 2026?

Workers’ Day (1 May) and Constitution Day (17 July). Workers’ Day is a public holiday under Article 2 of the Act on Public Holidays from 1 May 2026, and Constitution Day from 11 May 2026. [1]

Did a period for a patent procedure whose last day is 1 May change from 2026?

No. Article 14, subparagraph 4 of the Patent Act stated before 2026 as well that 1 May is included in public holidays. [3] What changed is that a substitute public holiday arises when Workers’ Day overlaps with a Saturday or Sunday. [2]

Are trademark and design deadlines the same?

There are provisions of the same form. Article 16, subparagraph 4 of the Trademark Act and Article 16, subparagraph 4 of the Design Protection Act provide for the case where the last day of a period is a public holiday. [4] Both provisions include Saturdays and Workers’ Day. [4]

If the term of a patent ends on a public holiday, is it extended by one day?

No. The Guidelines give the expiration date of the term of the patent as an example to which Article 14, subparagraph 4 of the Patent Act does not apply. [7]

How DEFINE IP Law Firm handles this

When the Korean statutes on public holidays change, DEFINE IP Law Firm recalculates the deadlines of pending cases. When we report a deadline, we state both the last day before it moves for a public holiday and the expiration date after it moves. We calculate the period for filing a revocation action separately, under Article 161 of the Civil Act. For questions about Korean public holidays and the calculation of IP deadlines, please write to contact@defineip.kr.

Sources

1. Ministry of Personnel Management (인사혁신처), Act on Public Holidays (공휴일에 관한 법률) (Act No. 21338, promulgated 2026-02-10, in force from 2026-05-11. Act No. 21543, promulgated 2026-04-09, in force from 2026-05-01. Enacting Act No. 18291, in force from 2022-01-01). Articles 2, 3 and 4, Addenda, text of the amendments, statement of reasons for the amendment (provided by the Ministry of Government Legislation), list of versions by enforcement date. https://www.law.go.kr/법령/공휴일에관한법률 (verified 2026-10-09)
2. Ministry of Personnel Management (인사혁신처), Regulations on Public Holidays of Government Offices (관공서의 공휴일에 관한 규정) (Presidential Decree No. 36290, promulgated 2026-04-30, in force from 2026-05-01, in part from 2026-05-11. Previous version Presidential Decree No. 33448, in force from 2023-05-04). Articles 2, 3 and 4, Addenda, text of the amendment, list of versions by enforcement date. https://www.law.go.kr/법령/관공서의공휴일에관한규정 (verified 2026-10-09)
3. Patent Act (특허법) (Act No. 21134), in force from 2025-11-11. Articles 3, 5, 14, 15 and 186, Addenda (Act No. 21134). Article 14 of the previous version (Act No. 21065) and of the version scheduled to enter into force (Act No. 21955, in force from 2027-03-16). https://www.law.go.kr/법령/특허법 (verified 2026-10-09)
4. Utility Model Act (실용신안법) (Act No. 21065), Article 3; Trademark Act (상표법) (Act No. 21134), Articles 16 and 162; Design Protection Act (디자인보호법) (Act No. 21065, in force from 2025-11-28), Articles 16 and 166; the same Articles of the versions scheduled to enter into force (Utility Model Act, Act No. 21953; Design Protection Act, Act No. 21951; in force from 2027-03-16); Act on the Designation of Workers’ Day (노동절 제정에 관한 법률) (Act No. 21134, in force from 2025-11-11), main text and Addenda Art. 2; Act on National Holidays (국경일에 관한 법률) (Act No. 12915), Article 2. https://www.law.go.kr/법령/상표법 (verified 2026-10-09)
5. Civil Act (민법) (Act No. 21454), in force from 2026-03-17, Articles 157 and 161. Civil Procedure Act (민사소송법) (Act No. 21993), in force from 2026-10-02, Article 170. Administrative Litigation Act (행정소송법) (Act No. 21615), in force from 2026-05-12, Article 8. The same Articles of the versions scheduled to enter into force (Civil Procedure Act, Act No. 21455; Administrative Litigation Act, Act No. 21461; in force from 2028-03-01). https://www.law.go.kr/법령/민법 (verified 2026-10-09)
6. Supreme Court Decision 2013Hu1573 Decided February 13, 2014 (대법원 2014. 2. 13. 선고 2013후1573 판결). https://www.law.go.kr/판례/(2013후1573) (verified 2026-10-09)
7. Ministry of Intellectual Property (지식재산처), Patent Examination Guidelines (특허·실용신안 심사기준) (MOIP Established Rule No. 7), in force from 2026-03-13. Part 1, Chapter 3, Periods; Part 6, Chapter 3, Applications with a Priority Claim under the Treaty. https://www.law.go.kr/행정규칙/특허·실용신안심사기준 (verified 2026-10-09)
8. Korea AeroSpace Administration (우주항공청), press release “「2027년 월력요항」 발표” (announcement of the Calendar Summary for 2027), 2026-06-29. https://www.kasa.go.kr/prog/plcyBrf/brief/kor/sub01_01_04/view.do?plcyBrfNo=431 (verified 2026-10-09)
9. Supreme Court Order 2006Ma851 Dated June 12, 2008 (대법원 2008. 6. 12.자 2006마851 결정); Supreme Court Order 2020Mo3694 Dated January 14, 2021 (대법원 2021. 1. 14.자 2020모3694 결정). https://www.law.go.kr/판례/(2006마851) (verified 2026-10-09)
10. Patent Court Decision 2023Heo11791 Decided January 10, 2024 (특허법원 2024. 1. 10. 선고 2023허11791 판결) (written judgment in “Major Decisions of Our Court” on the website of the Intellectual Property High Court of Korea). https://patent.scourt.go.kr/dcboard/new/DcNewsViewAction.work?seqnum=26250&gubun=44 (verified 2026-10-09)