Overlapping Business Hours Between Major Cities
When two teams work in different time zones, the number of shared working hours decides how easy collaboration is. The tables below show how many hours of a 09:00 to 17:00 working day overlap between ten major cities in January and in July.
How to read the tables
Each cell is the number of hours that both cities are inside 09:00 to 17:00 local time on the same day. A dash means there is no overlap. The values are calculated from the time zone database for a mid-January and a mid-July date, so they include each city's daylight saving rules.
January
| New York | Los Angeles | São Paulo | London | Berlin | Dubai | New Delhi | Singapore | Tokyo | Sydney | |
|---|---|---|---|---|---|---|---|---|---|---|
| New York | — | 5h | 6h | 3h | 2h | – | – | – | – | – |
| Los Angeles | 5h | — | 3h | – | – | – | – | – | 1h | 3h |
| São Paulo | 6h | 3h | — | 5h | 4h | 1h | – | – | – | – |
| London | 3h | – | 5h | — | 7h | 4h | 2.5h | – | – | – |
| Berlin | 2h | – | 4h | 7h | — | 5h | 3.5h | 1h | – | – |
| Dubai | – | – | 1h | 4h | 5h | — | 6.5h | 4h | 3h | 1h |
| New Delhi | – | – | – | 2.5h | 3.5h | 6.5h | — | 5.5h | 4.5h | 2.5h |
| Singapore | – | – | – | – | 1h | 4h | 5.5h | — | 7h | 5h |
| Tokyo | – | 1h | – | – | – | 3h | 4.5h | 7h | — | 6h |
| Sydney | – | 3h | – | – | – | 1h | 2.5h | 5h | 6h | — |
July
| New York | Los Angeles | São Paulo | London | Berlin | Dubai | New Delhi | Singapore | Tokyo | Sydney | |
|---|---|---|---|---|---|---|---|---|---|---|
| New York | — | 5h | 7h | 3h | 2h | – | – | – | – | – |
| Los Angeles | 5h | — | 4h | – | – | – | – | – | – | 1h |
| São Paulo | 7h | 4h | — | 4h | 3h | 1h | – | – | – | – |
| London | 3h | – | 4h | — | 7h | 5h | 3.5h | 1h | – | – |
| Berlin | 2h | – | 3h | 7h | — | 6h | 4.5h | 2h | 1h | – |
| Dubai | – | – | 1h | 5h | 6h | — | 6.5h | 4h | 3h | 2h |
| New Delhi | – | – | – | 3.5h | 4.5h | 6.5h | — | 5.5h | 4.5h | 3.5h |
| Singapore | – | – | – | 1h | 2h | 4h | 5.5h | — | 7h | 6h |
| Tokyo | – | – | – | – | 1h | 3h | 4.5h | 7h | — | 7h |
| Sydney | – | 1h | – | – | – | 2h | 3.5h | 6h | 7h | — |
What the numbers show
- Neighbors in longitude overlap the most. London and Berlin share most of the day, and so do Singapore and Tokyo.
- Opposite sides of the world have little or none. A team in Tokyo or Sydney and a team in New York or São Paulo cannot both work a normal day at the same time, so one side has to start early or finish late.
- Daylight saving time changes the picture. Compare the two tables for pairs such as London and Dubai or Singapore and Sydney: the overlap is different in January and July, because only one city in each pair changes its clocks.
- Dubai and New Delhi sit in the middle. Their working days overlap with both Europe and East Asia, so they are natural meeting points between those regions.
When there is no overlap
If your two cities show a dash, you have three practical choices: stretch the day on one side for a short call, rotate the inconvenient time between the teams, or work asynchronously with written updates and recorded videos. The scheduling guide explains how to share the inconvenience fairly.
Check your own pair: choose a date and a city in Time Compare. The colored bar shows which hours fall inside 09:00 to 18:00 there.
Related guides
Time Zones in Africa and the Middle East
Africa and the Middle East use few daylight saving changes. See the main offsets, the exceptions such as Egypt and Morocco, and the weekends that differ from Europe.
Time Zones in Canada, Latin America and the Caribbean
Canada has six time zones, Mexico four, Brazil four. See which countries change their clocks, which stopped, and how to schedule across the Americas.
UTC and Time Zone Offsets: How to Calculate Time Differences
Learn what UTC is, how to read offsets like UTC+5:30, and how to convert time between any two cities step by step.