Time difference between Tokyo and Buenos Aires

The gap holds all year

Neither city changes its clocks — Tokyo does not change its clocks and Buenos Aires does not change its clocks — so 12 hours is the difference in January and in July alike. That is worth knowing about this pair specifically, because most international pairs do move and a recurring meeting between them does not need checking twice a year.

About Tokyo and Buenos Aires

Japan is UTC+9 with no daylight saving anywhere, and has not had it since the occupation ended in 1952. The whole country runs one zone and the business day starts early, so the useful overlap with Europe is Japan's late afternoon.

Argentina is UTC−3 and fixed, and sits at a longitude that would suggest UTC−4 — the country is effectively on permanent summer time and has been since 1969, with brief exceptions.

What 12 hours actually costs you

There is no shared working hour at all. Nine to five in Tokyo is 9:00 PM to 5:00 AM in Buenos Aires. Somebody has to be outside their working day, and the only question is who — so the useful thing is to decide that once rather than rediscover it every time.

The least painful slot is 5:00 AM in Tokyo, which is 5:00 PM in Buenos Aires. That is 4 hours outside somebody's working day and it is the smallest that gap gets — every other hour of the clock costs more.

At 12 hours the two are far enough apart that the date stops matching. Midday in Tokyo is 12:00 AM the same day in Buenos Aires, but the ends of the working day do cross. "Tomorrow morning" means different things to the two of you, and a deadline given without a date attached will be missed by one side or the other.

When they can both be at their desks

Nine-to-five in Tokyo and nine-to-five in Buenos Aires do not overlap at all. With 12 hours between them, one side is always outside working hours, and the practical question is which side takes the early start or the late finish rather than when to meet.

Tokyo

Buenos Aires

00061218

How far apart Tokyo and Buenos Aires are

The shortest path over the Earth's surface between the two is 18,373 km (11,417 miles). That is beyond the range of almost every airliner in service, so in practice this journey is made with at least one stop, and the time in the air alone comes to around 22 hours 40 minutes.

Over that distance you cross 12 hours of clock, which is where jet lag comes from: the body shifts by about an hour a day, so 12 hours takes most people 12 days or so to absorb. Flying west to Buenos Aires is the easier direction — you gain the hours, and staying up later comes more naturally than going to bed early.

Tokyo to Buenos Aires, hour by hour

On the usual gap of 12 hours.

Frequently asked questions