Which zone this page means. South Korea does not observe daylight saving, so KST applies all year. It shares an offset with Japan. CST means US Central Standard Time (UTC-6) and also China Standard Time (UTC+8) — fourteen hours apart. This page means the US zone. For the Chinese zone see China Standard Time.
KST is ahead of CST by 14 hours today
On 19 August 2026, Korea Standard Time is on KST at UTC+09:00 and Central Standard Time (US) is on CDT at UTC-05:00. The gap between them is 14 hours, with CST behind. So 9:00 am in KST is 7:00 pm in CST, and 5:00 pm in KST is 3:00 am in CST. Going the other way, see CST to KST.
The gap is not constant, and that is the part that catches people out
Central Standard Time (US) is currently observing daylight saving and changes next on 1 November 2026. Korea Standard Time does not observe daylight saving, so the gap moves only when Central Standard Time (US) changes its clocks — twice a year, by one hour.
When you can actually both be at work
Taking a working day as 9:00 am to 5:00 pm local at each end, there are 0 overlapping hours in a normal day. There is none: the two working days do not touch at all, so any live meeting between Korea Standard Time and Central Standard Time (US) has to sit outside somebody's normal hours. The table above shows which end has the shorter stretch to give up.
Zone rules are set by legislation and change, sometimes at short notice. This page is built against tzdata 2026a, last reviewed 2026-08-18. Quarterly. Zone rules change by legislation, sometimes at short notice. Version and review date are shown on every zone page. The converter above reads your browser's own copy of the zone database, so if a rule has changed since this page was built the live answer follows the new rule.
Every convention used above — whether the start date counts, how month ends are clamped, which holidays close an office — is written out on the methodology page, including the daylight-saving rules behind the 14-hour gap above.