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.