Seoul's broad seasonal swing
At 37.6° N and sitting west inside the UTC+9 zone, Seoul ranges from about 9 hours 35 minutes of daylight in December to 14 hours 45 minutes in June. Sunrise comes before 05:15 in June and after 07:40 in January, Seoul time — a spread that shifts the whole rhythm of the city between seasons.
East-of-zone quirk
Korea Standard Time is anchored well west of the peninsula's solar position, so solar noon in Seoul lands close to 12:30 on the clock and early sunrises are the norm. Haze from the surrounding basin softens golden hour, but the Namsan and Bukhansan ridgelines give true-horizon views that match the calculator closely.
Sources and standards
Where these figures come from
Every formula on this page is implemented from the published reference material below. Where a value depends on a regional code, the calculator lets you override it rather than assuming one jurisdiction.
- NOAA Global Monitoring Laboratory — Solar Calculator — the solar position algorithm underlying sunrise, sunset and solar noon.
- NASA Science — Sun — solar geometry and the definition of civil, nautical and astronomical twilight.
- NIST Time and Frequency Division — time standards and the definition of the day.
Figures, formulas and reference tables last verified: 24 September 2026.