City-to-City Time Difference & Meeting Overlap Planner — ZYCalculator

A city time difference tool compares exact hour offsets and overlapping business meeting windows between any two world cities using IANA timezone rules.

Formula & Method

Time Difference = Destination_Offset - Origin_Offset (with IANA DST rules)

How to Use

  1. Pick Origin & Destination Cities: Select popular pairs or custom origin/destination world cities.
  2. Compare Live Clocks & Offsets: View exact time difference in hours, local dates, and live seconds.
  3. Find Shared Business Hours: Use the 24-hour synchronization table to schedule international calls and meetings.

Frequently Asked Questions

How many hours difference between London and New York?

London (GMT/BST) is 5 hours ahead of New York (EST/EDT) during standard daylight saving time. When it is 2:00 PM in London, it is 9:00 AM in New York.

What is the best overlapping meeting time between US and UK?

The optimal meeting window is 14:00 to 17:00 London time, which corresponds to 09:00 to 12:00 New York time, falling directly within standard business working hours in both countries.

How does daylight saving time affect city time differences?

Because countries change clocks on different dates in March and October/November, the difference between London and New York temporarily contracts to 4 hours for 2-3 weeks.