Holidays
South Korea's major holidays through 2028 — including Seollal and Chuseok, both tied to the lunar calendar and genuinely different in structure from most Western holiday calendars.
South Korean law distinguishes "national holidays" from "legally designated holidays," and only the former qualify for a substitute day off if they fall on a Sunday or overlap another holiday — New Year's Day and Memorial Day are legally designated and get no substitute, while Seollal and Chuseok (each a 3-day block) do. This split explains why some years get an unexpected extra day off around a given holiday and others don't, even when the underlying calendar situation looks similar.
Seollal and Chinese New Year fall on the same date almost every year, since both are based on the same East Asian lunisolar calendar tradition — this table's Seollal dates and this site's Chinese New Year dates are consistent with each other for exactly that reason.
The Korean government occasionally declares one-off temporary public holidays to bridge a gap between a holiday and a weekend, creating an extended break — these aren't part of any fixed yearly rule and are announced separately, so a specific year's actual total time off can end up longer than this baseline list suggests.
Related
The closely related lunar new year observed across East Asia.
A neighboring country's very differently structured calendar.
Check the current time alongside the holiday calendar.