The calculation
- Take the time difference d. If it is over 12, use 24 − d (the effective difference).
- With a 9-hour day on both sides (9am–6pm), overlap = 9 − effective difference (never below 0). For a 9-to-5, use 8.
- To share two hours a day, the two sides together must shift effective difference − 7 hours.
Overlap from New York (9am–6pm, winter)
| Other city | Difference | Effective | Overlap as is | For 2 hours |
|---|---|---|---|---|
| Los Angeles | −3 | 3 | 6 h | As is |
| London | +5 | 5 | 4 h | As is |
| Berlin | +6 | 6 | 3 h | As is |
| India | +10:30 | 10.5 | 0 | Shift 3.5 h in total |
| Tokyo / Seoul | +14 | 10 | 0 | Shift 3 h in total |
| Singapore | +13 | 11 | 0 | Shift 4 h in total |
| Sydney | +16 | 8 | 1 h | Shift 1 h in total |
Sydney example: 9–10am in Sydney is 5–6pm the previous day in New York. Figures apply from 1 November 2026 to 13 March 2027, while New York and Europe are on standard time and Sydney on daylight time.
Decision checklist
- Is the team built on fixed meetings or on async writing?
- Does the overlap fall in your morning or your night? Many people find early starts easier to sustain than late finishes.
- Does DST add or remove an hour of overlap for part of the year?
- How are days handled when one country has a holiday and the other doesn’t?
Check it in the app
See the whole day in the overlap view
The Overlap view on the Meeting tab of World Time Board colours 24 cells per city (work, early/late, night) and writes under each hour how many cities are in work hours. A column showing 2 is an hour you and the other city share.
Try a different schedule
Change Work hours in Settings, or set Custom work hours for one city, and the grid repaints at once. “What if I start at 7?” becomes a number you can see.
FAQ
What counts as early/late?
Two hours before work starts and four hours after it ends. With the default 9–18, that is 7–9 and 18–22.
Some Middle East companies have a different weekend.
Yes, Saudi Arabia, for example, takes Friday and Saturday off. The app’s weekend setting uses local Saturday and Sunday, so allow for this yourself.
World Time Board - Time Zones
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