When it is 09:00 in London it is 06:00 in Buenos Aires in January and 05:00 in July. Buenos Aires is 3 hours behind London right now — but it is not constant: the difference is 3 hours behind in January and 4 hours behind in July. This page gives the live times in both cities, the overlap between their working days, the daylight saving dates that move the difference, and the best meeting windows.
Try the tool: Time Zone Converter — convert any time between London and Buenos Aires, with the offset for the date you pick.
Live times in London and Buenos Aires
The two cities side by side. The January column uses the winter offsets (London UTC+00:00, Buenos Aires UTC−03:00); the July column uses the summer offsets (London UTC+01:00, Buenos Aires UTC−03:00).
| Time in London | Buenos Aires in January | Buenos Aires in July |
|---|---|---|
| 00:00 | 21:00 | 20:00 |
| 06:00 | 03:00 | 02:00 |
| 09:00 | 06:00 | 05:00 |
| 12:00 | 09:00 | 08:00 |
| 15:00 | 12:00 | 11:00 |
| 17:00 | 14:00 | 13:00 |
| 21:00 | 18:00 | 17:00 |
The world clock shows the current time in both cities live, and the individual city pages — time in London and time in Buenos Aires — explain each city's time zone, offsets and daylight saving in full.
The time difference between London and Buenos Aires
The difference is not constant. In January Buenos Aires is 3 hours behind London; in July it is 4 hours behind London. The difference changes on Sunday, 29 March 2026 (from 3 hours behind to 4 hours behind) and Sunday, 25 October 2026 (from 4 hours behind to 3 hours behind) — those are the dates when one of the two cities changes its clocks and the other does not, or when they change on different days. Between those dates the difference is one value; outside them it is the other.
To convert a time, add the difference: 09:00 in London is 06:00 in Buenos Aires in January and 05:00 in July; 17:00 in London — the end of the working day — is 14:00 in Buenos Aires in January and 13:00 in July. To go the other way, subtract it: 09:00 in Buenos Aires is 12:00 in London in January. The time difference calculator does the arithmetic for any date, and the UTC to Buenos Aires page gives the full conversion table for Buenos Aires.
Meeting overlap between London and Buenos Aires
The overlap is the hours when both cities are in their working day (09:00–17:00 local time). The table marks the overlapping hours in London's working day and shows what time they are in Buenos Aires.
January
| London time | Buenos Aires time | Both working? |
|---|---|---|
| 09:00 | 06:00 | No |
| 10:00 | 07:00 | No |
| 11:00 | 08:00 | No |
| 12:00 | 09:00 | No |
| 13:00 | 10:00 | No |
| 14:00 | 11:00 | No |
| 15:00 | 12:00 | No |
| 16:00 | 13:00 | No |
July
| London time | Buenos Aires time | Both working? |
|---|---|---|
| 09:00 | 05:00 | Yes |
| 10:00 | 06:00 | Yes |
| 11:00 | 07:00 | Yes |
| 12:00 | 08:00 | Yes |
| 13:00 | 09:00 | Yes |
| 14:00 | 10:00 | Yes |
| 15:00 | 11:00 | Yes |
| 16:00 | 12:00 | Yes |
In January the overlap is 0 hours: there is no hour when both cities are in their working day. In July it is 8 hours: 09:00, 10:00, 11:00, 12:00, 13:00, 14:00, 15:00, 16:00 London time. The meeting planner finds the overlap for any two cities and any date, and the meeting time finder finds it for a whole team.
Daylight saving in London and Buenos Aires
London observes daylight saving: in 2026 the clocks go forward on 29 March 2026 and back on 25 October 2026, moving the offset from UTC+00:00 to UTC+01:00.
Buenos Aires does not observe daylight saving, so its offset of UTC−03:00 never changes.
The difference changes on Sunday, 29 March 2026 and Sunday, 25 October 2026 in 2026. On those dates, one city changes its clocks and the other does not — or they change on different days — so the difference moves by an hour. A standing meeting set in one city's local time will land an hour early or late on the other side until the second city catches up. The fix is to set the calendar event in UTC, or to check the overlap again after each change. The individual DST pages — London DST 2026 and Buenos Aires DST 2026 — give the exact dates for each city.
Best meeting windows
In July the best windows are 09:00–17:00 in London (05:00–13:00 in Buenos Aires) — the same logic, with the July offsets.
Calling and travel notes
When it is 09:00 in London it is 06:00 in Buenos Aires in January; when it is 12:00 in London it is 09:00 in Buenos Aires; when it is 17:00 in London it is 14:00 in Buenos Aires. The difference is under 12 hours, so the two cities are usually on the same date — but check the date for late-evening and early-morning times, when the date can differ by a day. Scheduling between the Americas and Europe is the easiest intercontinental case: the difference is 5–9 hours, so the working days overlap for several hours. The best window is late morning in London and afternoon in Buenos Aires (or the reverse), when both sides are in their working day. Watch the three weeks in March when the United States has changed its clocks and Europe has not — the overlap shifts by an hour, and standing meetings land at the wrong time.
Worked conversions
Six conversions, for January (offsets London UTC+00:00, Buenos Aires UTC−03:00):
| London | Buenos Aires |
|---|---|
| 08:00 | 05:00 |
| 09:00 | 06:00 |
| 12:00 | 09:00 |
| 14:00 | 11:00 |
| 17:00 | 14:00 |
| 20:00 | 17:00 |
In July, add 1 hour to each Buenos Aires time. For the reverse direction, see Buenos Aires to London time.
London and Buenos Aires at a glance
| Fact | London | Buenos Aires |
|---|---|---|
| Country | United Kingdom | Argentina |
| Region | Europe | Americas |
| IANA time zone | Europe/London |
America/Argentina/Buenos_Aires |
| Standard offset | UTC+00:00 | UTC−03:00 |
| Daylight saving offset | UTC+01:00 | — does not observe |
| Offset in January 2026 | UTC+00:00 | UTC−03:00 |
| Offset in July 2026 | UTC+01:00 | UTC−03:00 |
| Observes daylight saving | Yes | No |
The table is the whole pair in one place. The two numbers that matter most are the January and July offsets: if they are the same in both columns for a city, that city's offset never changes; if they differ, the city observes daylight saving and the difference between the cities moves with it. The individual city pages — time in London and time in Buenos Aires — explain each city's time zone, and the DST pages — London DST 2026 and Buenos Aires DST 2026 — give the exact change dates.
Frequently asked questions
What is the time difference between London and Buenos Aires?
Buenos Aires is 3 hours behind London right now. In January the difference is 3 hours behind and in July it is 4 hours behind — it changes with daylight saving.
How do I schedule a recurring meeting between London and Buenos Aires?
Pick a time inside the overlap — the edge of the day, since there is no overlap — and set the calendar event in UTC so it moves correctly when the clocks change. Re-check the overlap in March and October, when the difference moves, and rotate the time if the meeting falls outside someone's working day.
What time is it in Buenos Aires when it is 09:00 in London?
It is 06:00 in January and 05:00 in July. The time zone converter gives the answer for any date.
What is the best time for a meeting between London and Buenos Aires?
There is no hour inside both working days. Meet at the edge of the day — early morning in one city, evening in the other — and rotate the awkward hour.
Does the time difference between London and Buenos Aires change during the year?
Yes. It changes on Sunday, 29 March 2026 and Sunday, 25 October 2026 in 2026, when one city changes its clocks and the other does not.
What time is it in London when it is 09:00 in Buenos Aires?
It is 12:00 in January and 13:00 in July. See Buenos Aires to London time for the full comparison from Buenos Aires's side.
What are the time zones of London and Buenos Aires?
London is in Europe/London (UTC+00:00 standard time) and Buenos Aires is in America/Argentina/Buenos_Aires (UTC−03:00 standard time).
What time is it in London when it is midnight in Buenos Aires?
It is 03:00 in London in January and 04:00 in July — the previous day, because Buenos Aires is ahead of London. Midnight conversions are the ones that most often land on the wrong date, so always check the date as well as the time.
Sources
- IANA Time Zone Database, via Node.js Intl (
Intl.DateTimeFormatwithtimeZone) — offsets, daylight saving dates and local times in this article were worked out from the IANA database, not typed from memory. - TimeFlow's own time-zone data (
data/cities.ts,data/dst.ts), computed from the IANA database. - TimeFlow's time zone converter and meeting planner — the live tools behind the numbers on this page.
- Time-zone and daylight saving rules are set by governments and can change. For flights, deadlines and meetings that cannot move, confirm the time with an official source.