Korea Standard (KST)
Seoul operates on Korea Standard (KST). This time zone does not observe Daylight Saving Time.
Time Zone: Korea Standard Time (KST) — Standard Offset: UTC+9 (KST) — DST: Not observed
Country: South Korea
This city does not observe Daylight Saving Time. The UTC offset remains constant year-round, which simplifies international scheduling.
Seoul operates on KST (UTC+9), the same offset as Tokyo. South Korea does not observe DST, keeping the time constant year-round. As the home of Samsung, LG, Hyundai, SK Group, and the global K-pop and Korean entertainment industry, Seoul is a major hub for technology, manufacturing, and cultural exports. The Korean Wave (Hallyu) has made KST relevant to entertainment schedules worldwide — album drops, concert announcements, and streaming premieres often follow Korean midnight or morning timing.
Korean business culture emphasizes long hours and dedication. While official hours run 9 AM to 6 PM, the reality in many Korean companies extends well beyond. The Korea Exchange (KRX) trades from 9:00 AM to 3:30 PM KST. Seoul shares the UTC+9 offset with Tokyo, making Korea-Japan business coordination seamless — no time conversion needed for the two largest economies in Northeast Asia.
Seoul's UTC+9 offset creates a 14-hour gap with New York (13 during EDT) and a 9-hour gap with London (8 during BST). The US overlap window mirrors Tokyo's: early morning Seoul (8-9 AM KST) catches the previous evening on the US East Coast (6-7 PM ET). For European coordination, afternoon Seoul works best — 3 PM KST = 6 AM GMT, catching the start of London's day.
Seoul and Tokyo sharing UTC+9 is significant — the two cities are major trading partners despite historical tensions. The 1-hour difference with China/Singapore/Hong Kong (UTC+8) makes Northeast to Southeast Asian coordination easy. Seoul's tech industry frequently collaborates with Silicon Valley, typically through shifted schedules or asynchronous workflows given the 17-hour difference with San Francisco.