How to Find the Best Time to Call Internationally

Calling across time zones doesn't have to be guesswork. Our free tool calculates the overlap between two cities' business hours, accounting for time zone differences of up to 14 hours. Simply select your city and their city, and we instantly highlight every window where both parties are likely awake and working.

We consider 9am–6pm as core business hours and flag late-evening slots (after 9pm) so you can avoid accidental midnight calls. The tool works for any pair of cities worldwide — from New York to Tokyo, London to Sydney, or Berlin to São Paulo.

Frequently Asked Questions

What is the best time to call between the US and Europe?

The sweet spot is typically 9am–12pm Eastern Time (ET), which corresponds to 3pm–6pm Central European Time (CET). This 3-hour window gives both sides a comfortable slot within business hours.

How do I call someone in a different time zone without waking them up?

Use this tool to check the overlap window. A good rule of thumb: stick to 9am–6pm in the recipient's local time. Our tool highlights any slot that falls outside these hours in amber or red.

Is there any good time to call between New York and Tokyo?

New York and Tokyo are 13–14 hours apart, making overlap very limited. The best window is 8am–9am EST (9pm–10pm JST) — just barely within reasonable hours. Early morning in New York is the only viable option for same-day calls.

What time zone converter is most accurate?

This tool uses the IANA time zone database via the browser's built-in Intl API, which automatically handles daylight saving time changes for every city listed. No manual DST adjustments needed.