Seoul to Sydney time
Seoul and Sydney sit just one or two hours apart, but because Australia's daylight saving runs during the southern-hemisphere summer, the gap flips with the season — enter the exact date and the tool works it out for you.
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Why the Seoul–Sydney gap swings between one and two hours
Seoul runs on KST (UTC+9) and never observes daylight saving. Sydney, by contrast, switches between standard time (AEST, UTC+10) and summer time (AEDT, UTC+11) — and because it's in the southern hemisphere, its seasons are the reverse of ours. So while Sydney is on summer time, roughly October to April, it's 2 hours ahead of Seoul; through the Australian winter, April to October, it's just 1 hour ahead. Sydney is the only side that ever moves, so a simple rule works: keep Seoul's time as it is and add either one or two hours. The shift is small, so the two cities' working hours overlap generously.
It's 9 a.m. in Seoul — what does the clock say in Sydney?
Say it's January and Australia is in summer: 9 a.m. in Seoul is 11 a.m. in Sydney (AEDT, +2). Come July, with Australia in winter, that same 9 a.m. in Seoul is 10 a.m. in Sydney (AEST, +1). It works the other way too — a meeting or match that starts at 7 p.m. Sydney time lands at 6 p.m. in Seoul during winter, or 5 p.m. in summer. The changeovers happen around early April and early October, so a date a day or two either side can shift the gap; when in doubt, drop the exact date into the converter above.
Calls, flights, family, live sport — when the gap actually matters
A direct Incheon–Sydney flight takes about 10 hours, so an overnight departure usually lands in Sydney the next morning — work out the local arrival time first and pickups or hotel check-in get far easier to book. Australia is a popular destination for working-holiday and study visas, so many people have family or friends there; checking the gap helps you avoid calling at their breakfast or bedtime. And for live sport — the Australian Open in January, cricket, the A-League — convert the local start time back to Seoul and set an alarm so you don't miss the first ball.
Frequently asked questions
Is Sydney ahead of or behind Seoul?
Sydney is always ahead of Seoul. During the Australian summer (Oct–Apr) it's 2 hours ahead; through the Australian winter (Apr–Oct) it's 1 hour ahead. Because Seoul has no daylight saving, the direction never flips — Sydney is always the one in front.
Why does the difference change between one and two hours?
Because Sydney is in the southern hemisphere and observes summer time (AEDT, UTC+11) from around October to April — the months that are winter for us. During that window it sits at UTC+11, a 2-hour gap; the rest of the year it's on standard UTC+10, a 1-hour gap. Seoul stays on UTC+9 all year, so only Sydney moves.
How do I get the exact difference for a specific date?
Enter the date and time in the converter above and it automatically checks whether Sydney is on summer time that day, applying the correct 1- or 2-hour offset. This is especially useful around the early-April and early-October switchovers, when doing the math by hand is easy to get wrong.