Popular time zone conversions.
Choose a popular city pair or time zone conversion. Each page includes a ready-to-use converter and a clear explanation of how the time difference works.
Choose city time or a fixed offset
A city pair follows local clock rules on the date you select. New York–London therefore answers a different question from EST–UTC. EST means UTC−5 throughout the year in this converter; New York can use a different offset during daylight saving time. Choose the city pair when planning an appointment in a place, and a fixed reference when your source explicitly gives that offset.
Read the date-specific reference table
Each conversion page includes a table of matching times. Set the date before using it, then check the destination date as well as the hour. A late evening in the first city may already be tomorrow in the second. The annual intervals explain when a city pair’s time difference changes; the monthly working-hour windows help you compare daytime overlap.
For example, 09:00 in New York is 14:00 in London on 15 January 2026, but 13:00 on 15 March 2026. The cities change clocks on different weekends. Read the 2026 US–UK clock-change guide for the dates that affect a recurring morning call.
Compare another route or a larger team
The main converter accepts additional cities and IANA zone identifiers. Add up to 12 places to compare one moment across the whole group. Use the meeting planner when the full duration needs to fit everyone’s working day, and confirm personal availability separately.
If you are calculating a difference manually, our worked conversion examples show how to subtract the starting UTC offset and add the destination offset without losing minutes or crossing into the wrong calendar date.