UK to Korea Time: Difference & Converter

This page shows the current time difference between the United Kingdom and South Korea and explains how to convert times between the two. You enter a time in UK time (GMT/BST) and get the corresponding time in Korea (KST), or vice versa. The calculator below works out the conversion for any date you choose, automatically accounting for daylight saving time in the UK.

Formula

The conversion uses a simple formula:

Korea Time = UK Time + 9 hours − 1 hour (if UK is on BST)

Where:

• UK Time – the local time in the United Kingdom, in 24-hour format (e.g., 14:30 for 2:30 PM).
• UK daylight saving – 1 if the UK is currently in British Summer Time (BST, UTC+1), otherwise 0 for Greenwich Mean Time (GMT, UTC+0).
• Korea Time – the local time in South Korea, which is always UTC+9 (Korea Standard Time, KST).
• Date offset – an optional number of days to add to the current date (for planning ahead).

The result is given in 24-hour format. For example, 14:00 becomes 23:00 when Korea is 9 hours ahead.

Worked Example

Using the default values from the calculator:

• UK time: 12:00 (noon)
• UK daylight saving: No (0)
• Date offset: 0 days

Step 1: Add 9 hours to 12:00 → 21:00.

Step 2: Subtract 0 hours (no DST) → 21:00.

Step 3: No date offset → result is 21:00.

So 12:00 noon in London (GMT) is 21:00 (9 PM) in Seoul. The time difference is 9 hours.

Why the UK and Korea Have Different Time Zones

The United Kingdom is on Greenwich Mean Time (GMT, UTC+0) for most of the year, and switches to British Summer Time (BST, UTC+1) from the last Sunday in March to the last Sunday in October. South Korea, on the other hand, uses Korea Standard Time (KST, UTC+9) all year round – it does not observe daylight saving time. This means the difference between the two countries is either 8 hours (when the UK is on BST) or 9 hours (when the UK is on GMT).

The 9-hour offset comes from Korea’s longitude: it is about 135° east of Greenwich, and each 15° of longitude corresponds to one hour of time difference. Korea’s time zone is set to UTC+9, which aligns it with Japan and parts of Russia.

How to Convert Times Manually

If you need to convert a time without a calculator, follow these steps:

1. Determine whether the UK is currently on GMT or BST (check the date – BST runs from late March to late October).
2. Add 9 hours to the UK time if it’s GMT, or 8 hours if it’s BST.
3. If the result is 24 or more, subtract 24 and add one day to the date.
4. If the result is negative (when converting Korea to UK), add 24 and subtract one day.

For example, to convert 3:00 PM BST to Korea time: 15:00 + 8 = 23:00 (11 PM) same day. To convert 10:00 AM KST to UK time during GMT: 10:00 − 9 = 01:00 (1 AM) same day.

Common Mistakes and Misconceptions

One frequent error is forgetting that the UK switches to BST in summer. If you assume the UK is always on GMT, you’ll be off by one hour during the summer months. Another mistake is mixing up 12-hour and 24-hour formats – always use 24-hour time in calculations to avoid AM/PM confusion.

Also, note that the date can change. If it’s 10 PM in London (BST), adding 8 hours gives 6 AM the next day in Seoul. Always check whether the result crosses midnight.

Some people think Korea uses daylight saving time – it does not. KST is fixed at UTC+9 year-round, so the only variable is the UK’s DST status.

When to Use This Converter

This converter is useful for scheduling international calls, online meetings, or virtual events between the UK and South Korea. For example, if you’re in London and want to join a 10 AM webinar in Seoul, you’d need to be online at 1 AM (during BST) or 2 AM (during GMT).

It’s also handy for travel planning, sending messages to friends or family, or tracking deadlines for Korean businesses. Since the time difference is large, most cross-country communication happens in the late evening UK time or early morning Korea time.

The calculator also includes a date offset feature, so you can plan for a specific day in the future – useful for booking flights or setting reminders.

Time Zone Table: UK vs Korea

Here’s a quick reference for common times (UK time on the left, Korea time on the right, assuming GMT – add one hour to Korea if the UK is on BST):

• 00:00 (midnight) → 09:00 (9 AM)
• 06:00 (6 AM) → 15:00 (3 PM)
• 12:00 (noon) → 21:00 (9 PM)
• 18:00 (6 PM) → 03:00 (3 AM next day)

Remember: the table assumes GMT. During BST, subtract one hour from the Korea time shown.

Frequently Asked Questions

What is the time difference between UK and Korea right now?

It depends on the date. From late March to late October, the UK is on BST (UTC+1), so the difference is 8 hours (Korea is ahead). The rest of the year, the UK is on GMT (UTC+0), making the difference 9 hours. You can check the current date to determine which applies.

Does South Korea observe daylight saving time?

No. South Korea has used KST (UTC+9) year-round since 1988 and does not change its clocks. This simplifies conversions – only the UK’s DST affects the difference.

How do I convert 2 PM UK time to Korea time?

If the UK is on GMT, add 9 hours: 2 PM + 9 = 11 PM (23:00) same day. If the UK is on BST, add 8 hours: 2 PM + 8 = 10 PM (22:00) same day.

What is the best time to call someone in Korea from the UK?

Because Korea is 8-9 hours ahead, a good window is UK early morning (8-10 AM) which is Korea late afternoon (4-7 PM). Alternatively, UK late evening (9-11 PM) is Korea early morning (6-8 AM) – not ideal for most. Aim for UK morning to catch Korea’s afternoon.

Why is Korea 9 hours ahead of the UK?

Korea’s time zone is set to UTC+9, based on its longitude (about 135°E). The UK is at UTC+0 (GMT) or UTC+1 (BST). The difference in longitude translates directly into the time offset.

Is the time difference the same all year?

No. The difference is 9 hours during UK winter (GMT) and 8 hours during UK summer (BST). Since Korea doesn’t change its clocks, the variation comes solely from the UK’s daylight saving schedule.

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in t | UK time (24h) | - | 12:00 | 0
sel uk_dst | UK daylight saving? | No=0, Yes=1
in d | Date offset (days from today) | - | 0 | 0
out kst | Korea time (KST) | - | (t + 9 - uk_dst + d*24) % 24 | 0
out diff | Time difference (hours) | - | 9 - uk_dst | 0