City comparison · time difference and converter
London is 6 hours behind Haiphong right now. Haiphong sits in Vietnam on Bangkok; London sits in United Kingdom on London. They are roughly 9,302 km apart (5,780 mi), a flight of about 11h 57m. Haiphong's metro holds around 2.6 million people; London's around 9.5 million.
Slot 1
15:00 / 09:00
Haiphong / London
Both inside business hoursSlot 2
16:00 / 10:00
Haiphong / London
Both inside business hoursSlot 3
09:00 / 03:00
Haiphong / London
Partial overlapEach row is one hour in Haiphong. Green rows are inside business hours in both cities; amber means only one side is at their desk; grey rows fall outside business hours in both.
No public holidays in Vietnam or United Kingdom this month.
Great-circle distance
9,302 km
(5,780 mi)
Approximate flight
11h 57m
850 km/h cruise + 1h taxi/climb/descent
Jet lag
6h
Roughly 1 day to adjust per timezone crossed
The heatmap gives you the shape of the day. If you need to convert one specific hour — say a customer call or a release window — open the converter with both cities already loaded.
Open in converter →The difference between Haiphong and London is not really a number, it's a daily rhythm. London is 6 hours behind Haiphong on the clock today, but the lived version is that Haiphong is ahead in the calendar, so by the time London comes online, half of Haiphong's day is already gone. That gap, more than the raw offset, is what teams have to design around.
In Haiphong, the working day picks up earliest in the financial districts — Haiphong's downtown core wakes early and breaks for lunch at the usual hour. The mood in London is its own story: the Square Mile crowds Cannon Street at 08:00 and the pubs near Liverpool Street fill at 17:30. If you are scheduling between the two, the heatmap above marks the rows where both patterns line up.
Daylight saving is the other thing to keep an eye on. Vietnam either observes DST or holds a fixed offset year-round; United Kingdom follows the EU calendar (last Sunday of March and October). When the two changes are weeks apart, the offset between Haiphong and London is one hour off the usual for that stretch — a cliff that catches recurring calendar invites unless your calendar app rebases them automatically. Pin the meeting to a city, not an offset, and the tool handles the rest.
For travellers, the 11h 57m flight is the short version of the story. The longer one is jet lag: roughly one day of adjustment per timezone crossed, which means a trip across the 6-hour gap costs about 6 groggy days on each side. Pilots and cabin crew swear by morning sunlight and an early walk; whatever your routine, the wall-clock numbers above are the source of truth for your first morning in the new city.