Current Time in Seoul

A water clock, a curfew bell, and a moving time zone

Long before Seoul had a standard time, it had a state clock. In 1434, under King Sejong the Great, Joseon court astronomers built the Jagyeongnu, a self-striking water clock that used floats and falling metal balls to sound the hours automatically — a mechanism advanced enough that historians still study its escapement mechanism today. The city's daily rhythm was governed just as much by the Bosingak Bell in the old city center: 28 strikes at dusk (injeong) closed the gates and started the nightly curfew, and 33 strikes at dawn (paru) reopened them — 28 for the constellations that guard the four directions, 33 for the Buddhist heavens. The bell still rings today, most visibly as part of Seoul's New Year's Eve countdown.

Standard time itself has moved more than most people expect. Korea adopted its first national standard time in 1908, a UTC+8:30 offset based on the 127°30'E meridian running near Seoul — a genuinely local choice. That lasted only until Japan's 1910 annexation of Korea, when colonial authorities shifted the peninsula onto Japan Standard Time (UTC+9) in 1912 to align it with Tokyo. After liberation in 1945, South Korea reverted to its original UTC+8:30 in 1954 under President Syngman Rhee — widely read as a symbolic break from a colonial-era imposition. That didn't last either: in August 1961, the military government of Park Chung-hee shifted the country back to UTC+9, primarily for trade and logistics alignment with Japan, and Seoul has kept that offset ever since.

Planning around Seoul's real schedule

Beyond the standard 9:00–18:00 office day, a few Seoul-specific timing quirks matter for scheduling calls or visits:

• Business dinners (hoesik) routinely run into the evening, often past 9 or 10 PM — don't assume a Seoul colleague is free right after the nominal end of the workday.
• The Korea Exchange trades 9:00 to 15:30 KST, tighter than many Western markets, with no lunch pause.
• Seollal (Lunar New Year) and Chuseok (Korean thanksgiving), both set by the lunar calendar and each spanning a three-day national holiday, shut down business correspondence almost completely — check the lunar calendar dates each year rather than assuming a fixed date.
• Rush hour on the subway runs roughly 7:00–9:00 AM and 6:00–8:00 PM KST, among the busiest transit windows of any world capital.

Time differences from Seoul

Because Seoul never changes its own clock, every gap below moves only when the other city shifts for its own daylight saving.

Tokyo is the simplest comparison of all — the two cities have kept identical clocks for over sixty years.

Working hours and when to call

Most Seoul offices run roughly 9:00 to 18:00, Monday to Friday, and the Korea Exchange trades 9:00 to 15:30 KST with no lunch pause.

• From East Asia: a Seoul morning overlaps a Shanghai or Singapore morning almost entirely, given the small one-hour gaps.
• From Europe: minimal overlap; a Seoul morning call lands late at night in London or Paris.
• From the US East Coast: essentially no daytime overlap; the workable window is a Seoul evening meeting a New York morning.
• From Sydney: a comfortable near-full-day overlap given the small 1–2 hour gap.

Daylight through the year

At roughly 37.6°N, similar in latitude to San Francisco or Athens, Seoul sees a somewhat wider seasonal swing than tropical or equatorial cities — from about 9 hours 35 minutes around the December solstice to about 14 hours 43 minutes around the June solstice.

How we calculate this page: the live clock and UTC offset come from the IANA time zone database (Asia/Seoul). Sunrise, sunset, solar noon, twilight, and moon phase are computed from Seoul's coordinates (37.5665°N, 126.9780°E) using standard astronomical formulas, recalculated on every page load. Weather is pulled live from Open-Meteo. The history and scheduling notes above were researched and written specifically for Seoul.