A “long weekend” is when a Korean public holiday touches a weekend; a “sandwich” (bridge / 징검다리) day is a lone working day wedged between a holiday and a weekend, where one day of annual leave unlocks a 4-day or longer break. Both fall straight out of the holiday data this API already serves — including the substitute holidays (대체공휴일) that generic worldwide lists miss.
There is no single “long weekends” endpoint on purpose — what counts as a bridge day depends on your leave policy (does Saturday count? how many bridge days will you spend?). Instead, fetch the year's holidays once with /v1/holidays?year=YYYY, build a local Set of holiday dates, then walk the calendar: a day is “off” if it is a Saturday, Sunday or a holiday. Any run of 3+ consecutive off-days is a long weekend; a single working day with off-days on both sides (within your bridge budget) is a sandwich day worth taking. Because substitute holidays are already in the dataset, the awkward cases that break naive planners — a holiday landing on a Sunday and shifting to the next Monday — resolve correctly.
| GET | /v1/holidays?year=2026 |
All Korean public holidays for a year, incl. substitute holidays (대체공휴일) — fetch once, then scan for long weekends locally. |
| GET | /v1/holidays/is?date=2026-09-25 |
Is a single date a public holiday? Useful when checking the days around a candidate long weekend. |
| GET | /v1/today |
Today's Korean date (KST) and holiday status — handy for a 'next long weekend' countdown. |
# Fetch the year once, then find long weekends in your own code.
curl "https://korea-calendar-api.kunstudio.workers.dev/v1/holidays?year=2026"// From the 2026 holiday list, two standout breaks (weekdays are real):
//
// Chuseok 2026 — a natural long weekend, zero leave days:
// Thu 2026-09-24 추석 연휴 (holiday)
// Fri 2026-09-25 추석 (holiday)
// Sat 2026-09-26 추석 연휴 (holiday)
// Sun 2026-09-27 weekend
// => 4 days off (Thu–Sun) without taking any leave.
//
// Seollal 2026 — 2 bridge days unlock 9 days off:
// Sat 2026-02-14 weekend
// Sun 2026-02-15 weekend
// Mon 2026-02-16 설날 연휴 (holiday)
// Tue 2026-02-17 설날 (holiday)
// Wed 2026-02-18 설날 연휴 (holiday)
// Thu 2026-02-19 ← take as leave (bridge)
// Fri 2026-02-20 ← take as leave (bridge)
// Sat 2026-02-21 weekend
// Sun 2026-02-22 weekend
// => 9 continuous days off for only 2 days of annual leave.No API key is needed on the origin to try this — it is rate-limited for fair evaluation. See the OpenAPI spec for the full schema.
/v1/holidays?year=YYYY once and build a Set of holiday date strings. Mark each calendar day “off” if it is Sat, Sun or in that Set. A maximal run of 3+ off-days is a long weekend. A working day that is off-adjacent on both sides (within your chosen bridge-day budget) is a sandwich day. Do the scan locally so you never call the API in a loop.substitute: true. They are exactly what makes Korean long-weekend math tricky — a holiday on a Sunday rolls to the next non-holiday weekday — and the case generic worldwide holiday lists get wrong.Building a Korean fortune (사주/saju) app? Pair this with the KunStudio Saju API for a full four-pillars reading over REST.