Time Differences Between Major World Cities: A Reference
The hour gaps between the world's main business hubs — New York, London, Seoul, Tokyo, Sydney, Dubai — and how they shift with the seasons.
The transatlantic corridor
New York and London sit five hours apart for most of the year — London ahead — narrowing to four during the few weeks in spring and autumn when the US has changed its clocks and Europe has not. It is one of the friendliest major-city pairs: London's afternoon is New York's morning, giving the two financial centers a long shared window that global markets are effectively built around.
Continental Europe adds an hour: Paris, Berlin, and Frankfurt run six hours ahead of New York (CET/CEST against ET). The West Coast adds three more the other way — London is eight hours ahead of San Francisco and Los Angeles, leaving only the California morning and London evening as common ground.
East Asia against the West
Seoul and Tokyo share UTC+9 year-round with no daylight saving, which makes them stable anchors. Against New York the gap is 13 hours in the northern summer and 14 in winter — near-total inversion, where one side's business day is the other's night. Against London, Seoul and Tokyo are 8 hours ahead in summer and 9 in winter, leaving a workable window between a European morning and an East Asian evening.
Within Asia the gaps are small and constant: Beijing, Singapore, and Hong Kong at UTC+8 sit one hour behind Seoul and Tokyo, and India at UTC+5:30 is 3 hours 30 minutes behind Seoul — one of the pairs where the half-hour offset routinely surprises people.
The southern hemisphere twist
Sydney runs on UTC+10 in the southern winter and UTC+11 during its daylight saving summer, which spans roughly October to April. Because its shifts mirror the northern hemisphere's, Sydney's gap with London cycles through 9, 10, and 11 hours over the year, and its gap with New York swings between 14 and 16 hours — the maximum wobble a city pair can have.
Sydney against East Asia is far gentler: one to two hours ahead of Seoul and Tokyo depending on season. The genuinely hard part of Australian scheduling is with the Americas, where the date line means Sydney's Monday morning is still Sunday in New York and Los Angeles.
The middle of the map
Dubai at UTC+4, with no daylight saving, is the bridge zone: four hours ahead of London in winter, three in summer, five hours behind Seoul, and able to reach both Europe and East Asia inside a normal working day. That geographic luck is part of why Gulf hubs work well for globally distributed teams and layovers alike.
Treat every figure on this page as the pattern rather than the guarantee: daylight saving policies change, and a handful of regions adjust their rules in any given year. For an actual meeting, check the live difference between your two cities on the day you schedule it.