Time difference between London and Hong Kong

The gap is not the same all year

Every converter gives one number for this pair. That number is right for most of the year and wrong for part of it, because London goes forward on the last Sunday in March and back on the last Sunday in October and Hong Kong does not change its clocks.

Hong Kong stays put all year while London moves, so a meeting fixed in Hong Kong's calendar shifts by an hour twice a year at London's end.

About London and Hong Kong

London is the reference the rest of the system is measured from: Greenwich sits inside the city, and UTC±0 is its winter time. It does not stay there — Britain moves to UTC+1 for seven months of the year, which is why "London is GMT" is wrong more often than it is right.

Hong Kong is UTC+8 all year and has been since 1979, when it dropped a summer-time arrangement that had run intermittently since the 1940s. It shares the offset with mainland China, which simplifies a great deal.

What 7 hours actually costs you

The window is 1 hour wide and that is all there is. 9:00 AM–10:00 AM in London is 4:00 PM–5:00 PM in Hong Kong, and anything outside it puts somebody at their desk when they are not meant to be. A pair this tight is worth putting in a calendar rather than agreeing each time.

When they can both be at their desks

Nine-to-five in both cities overlaps for 1 hour — 9:00 AM to 10:00 AM in London, the same moment as 4:00 PM to 5:00 PM in Hong Kong.

London

Hong Kong

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How far apart London and Hong Kong are

The shortest path over the Earth's surface between the two is 9,623 km (5,979 miles). Flown along that line, an airliner at cruising speed takes roughly 12 hours 5 minutes in the air — actual routings add to it, and whether a nonstop service exists depends on the airlines rather than the distance.

Over that distance you cross 7 hours of clock, which is where jet lag comes from: the body shifts by about an hour a day, so 7 hours takes most people 7 days or so to absorb. Flying east to Hong Kong is the harder direction — you lose the hours and have to fall asleep earlier than your body wants.

London to Hong Kong, hour by hour

On the usual gap of 7 hours.

Frequently asked questions