What time is it in Korea? Korean Standard Time

Have you ever wondered what time it is in Korea? Perhaps you are planning a trip to Seoul or are simply curious about the Korean time zone. In this article, we will dive into Korea's time, its peculiarities, and interesting facts.

It is also worth reading our article on Japanese time, which covers JST and the 25-hour clock: What Time Is It in Japan? JST, Time Zones, and the 25-Hour Clock

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KST (Korea Standard Time)

The official time in South Korea is called KST, short for Korea Standard Time, known in Korean as 한국 표준시 (Hanguk pyojunsi). The country keeps UTC+9 all year, which puts it 12 hours ahead of Brasília (UTC-3).

It is interesting to note that South Korea, like Japan, does not observe daylight saving time. Therefore, the time difference remains constant throughout the year. If it is 3 PM in Brazil, it will be 3 AM the next day in Korea.

In addition to Japan, Korea shares its time zone with East Timor, Palau, the eastern part of Indonesia (Papua and Maluku) and Yakutsk in Russia. Jakarta runs two hours behind Seoul, Beijing one hour, and North Korea uses the same zone as the South.

The sunrise in Seoul moves with the seasons: close to 5:10 AM in June and around 7:45 AM in January. Sunset runs from about 5:20 PM in December to nearly 8 PM in June.

Time in Korea - Differences and Curiosities

Just like in Japan, Korea also counts beyond 24:00 in certain situations. The practice shows up in TV programming, work hours and even public transport, where 25:00 means 1 AM of the next day, so activities continue into the early morning without changing the date.

12-Hour Clock in Daily Life: Although the official system is 24 hours, in daily life, Koreans often use the 12-hour system, especially in informal conversations. They differentiate morning and afternoon using "오전" (ojeon, before noon) and "오후" (ohu, after noon).

Historical Influence on Time Measurement: During the period of Chinese influence, Korea adopted the zodiac system to count the hours, a reflection of the culture and philosophy shared with China. This ancient system divided day and night into 12 periods, each named after an animal of the Chinese zodiac.

Cultural Significance of Hours: Certain hours have cultural meanings in Korea. 4:44 AM or PM is often avoided, since the number "four", 사 (sa), sounds like the hanja 死, "death". For the same reason, many buildings skip the fourth floor.

Daylight Saving Time: South Korea used daylight saving time in 1948-1951, again in 1955-1960, and one last time in 1987-1988, around the Seoul Olympics. Since then, the clock has stayed at UTC+9 all year.

The History of Time and Clocks in Korea

In pre-modern Korea, time was measured differently from Western conventions. The traditional system divided the day into twelve periods, each named after an animal of the Chinese zodiac, and the length of each period changed with the seasons, since it was calculated from the amount of sunlight.

Before modernization, Korea followed a traditional time system, where each region had its own time calculation based on the sun. With the adoption of the standard time zone, Korea simplified time measurement across the country, especially after the expansion of the railway network.

Clocks were introduced to Korea in the 17th century, but water clocks and sundials had been in use for centuries. The UTC+9 zone that applies today arrived much later, in stages.

Water Clocks and Sundials

Koreans used water clocks called "물시계" (Mulsigye), common in Asia, to measure time by the flow of water. These devices were highly complex and crucial for keeping time in palaces and temples. The most famous water clock in Korea, the Jagyeongnu (자격루), was built in 1434 by Jang Yeong-sil (장영실) for King Sejong and struck the hour on its own with a bell, gong and drum.

In addition to water clocks, sundials called "해시계" (Haesigye) were also used to measure time during the day, especially in public places and temples. The bowl-shaped angbu-ilgu (앙부일구) was set up in 1437 so that anyone could read the hour in daylight.

Foreign Influences and Modernization

During the Joseon period, especially in the last centuries, Korea began to come into contact with Western technologies, including mechanical clocks. This foreign influence accelerated the modernization of the time measurement system in the country.

In the late 19th and early 20th centuries, Korea began to adopt the solar 24-hour time system, more aligned with international conventions. This movement was part of the modernization reforms.

Standardization of the Time Zone

In 1908, the Korean Empire adopted GMT+8:30, aligned with the 127°30′ east meridian, which runs through the peninsula. In 1912, during the Japanese occupation, the Governor-General moved the clocks to GMT+9, the same as Japan. In 1954, under President Syngman Rhee, South Korea returned to GMT+8:30, and in 1961 the military government of Park Chung-hee restored GMT+9, which remains in force today.

North Korea used UTC+8:30, Pyongyang Time, from August 2015 to May 2018, when it returned to UTC+9 to match the South.

One trace of that history survives in everyday life: because the standard meridian sits at 135° east, the official hour in Seoul runs about 30 minutes ahead of the city's own solar noon.

How to Tell Time in Korean?

Korean has two number systems, a native one (하나, 둘, 셋) and a Sino-Korean one (일, 이, 삼). Telling the time mixes the two: hours use the native numbers, and minutes use the Sino-Korean ones. "Three o'clock" is "세 시" (se shi), where "세" (se) is the native three, the short form of 셋 before a counter. The Sino-Korean three is "삼". Both systems are laid out in our list of numbers in Korean.

For hours, the number is followed by "시" (shi), which means hour. For minutes, the number is followed by "분" (bun). So "3:15" is "세 시 십오 분" (se shi ship-o bun), and "2:45" is "두 시 사십오 분" (du shi saship-o bun). For an exact hour, like "at three," just say "세 시" (se shi). Half past is "세 시 반" (se shi ban), with "반" meaning half.

Time of Day: Korea also uses the terms "오전" (ojeon) for a.m. (before noon) and "오후" (ohu) for p.m. (after noon). Therefore, "9:00 a.m." would be "오전 아홉 시" (ojeon ahop shi). Midnight is expressed as "자정" (jajeong), and noon as "정오" (jeong-o). To ask what time it is, the everyday polite form is "지금 몇 시예요?" (jigeum myeot siyeyo?).

The numbers 1 to 4 change shape before 시: 한 시, 두 시, 세 시, 네 시. Days, months and years follow a different pattern, explained in days of the week, months and years in Korean.

Time Difference Between Korea and the Rest of the World

South Korea keeps the same clock as Japan, East Timor, Palau and Yakutsk in Russia, and runs 1 hour ahead of China and 2 hours ahead of Jakarta and Bangkok. In Australia, the gap depends on the city and the season: Sydney sits 1 hour ahead of Seoul in standard time (AEST) and 2 hours ahead during daylight saving (AEDT).

The table below compares Seoul with the standard time of each place. Where the other country observes daylight saving, the difference shifts by one hour for part of the year.

Place	Difference from Seoul	Note
São Paulo, Rio de Janeiro, Buenos Aires	-12 hours	UTC-3
New York, Toronto, Montreal	-14 hours; -13 during local summer	EST/EDT
Dallas	-15 hours; -14 during local summer	CST/CDT
Mexico City	-15 hours	UTC-6, no DST since 2022
Los Angeles, Vancouver	-17 hours; -16 during local summer	PST/PDT
Lisbon, London, Dublin	-9 hours; -8 during local summer	GMT/BST, WET/WEST
Paris, Berlin, Madrid, Rome	-8 hours; -7 during local summer	CET/CEST
Athens, Kyiv	-7 hours; -6 during local summer	EET/EEST
Moscow	-6 hours	UTC+3, no DST
Johannesburg	-7 hours	UTC+2
Cairo	-7 hours; -6 during local summer	UTC+2, DST since 2023
Dubai, Riyadh	-5 hours	UTC+4
Tehran	-5 hours 30 minutes	UTC+3:30, no DST
New Delhi	-3 hours 30 minutes	UTC+5:30
Bangkok, Jakarta, Hanoi	-2 hours	UTC+7
Beijing, Hong Kong, Singapore, Manila	-1 hour	UTC+8
Tokyo, Dili, Palau	0	UTC+9
Yakutsk	0	UTC+9
Vladivostok	+1 hour	UTC+10
Sydney	+1 hour; +2 during Australian summer	AEST/AEDT
Auckland, Wellington	+3 hours; +4 during New Zealand summer	NZST/NZDT

Because KST is fixed at UTC+9, converting only depends on the other side's clock. For a call with Brazil, remember that 6 PM in Brasília is already 6 AM the next day in Seoul. Calling the other way is easier: early evening in Seoul lands in the Brazilian morning.