Time Zone Difference Calculator

Enter your departure time on a 24-hour clock, the UTC offsets of your origin and destination, and the flight length. The calculator gives the local time you land (with any change of date), the time difference, which direction you are shifting your body clock, a calling window that lines up with 9:00–17:00 at the destination, and a rough number of days to adjust.

The same difference answers everyday questions: what time it is for a colleague abroad, when to schedule a call, or whether a deadline "by end of day" in another country has passed. Set the flight duration to 0 to convert a single time between zones.

Offsets must be the ones in force on the day. Daylight saving time moves most of North America and Europe forward by an hour for part of the year, on different dates, and most of Asia, Africa and South America do not observe it. For flight lengths use the flight time calculator, and for a fuller sleep-shifting plan see the jet lag calculator.

UTC offsets are defined by each country's government and recorded in the IANA time zone database that phones and computers use. A few zones use half-hour or 45-minute offsets, such as India (UTC+5:30) and Nepal (UTC+5:45); enter these as decimals, 5.5 and 5.75. The recovery estimate assumes the body clock shifts about 1.5 hours a day eastward and 2 hours westward. This page also replaces the former meeting time across time zones calculator.

Standard and daylight saving offsets. Check the exact changeover dates for your travel: the US and Canada change on the second Sunday of March and first Sunday of November, the EU and UK on the last Sundays of March and October.

The calling window shows when the other side's 9:00–17:00 working day falls on your clock. For a meeting that works for both, look for the overlap with your own working hours:

• New York and London (5 hours apart): 9:00–12:00 in New York is 14:00–17:00 in London.
• US West Coast and Western Europe (8–9 hours): only early morning in California overlaps with late afternoon in Europe.
• US and India (9.5–10.5 hours): there is little or no overlap; one side usually joins early or late.
• Europe and Singapore or Hong Kong (6–7 hours): European mornings meet Asian afternoons.

Remember that the US and Europe change clocks on different weekends, so for one to three weeks in March and in October/November the usual gap is an hour smaller.

Your body clock takes the shorter way round. A trip from Los Angeles (UTC−7 in summer) to Tokyo (UTC+9) is a +16-hour difference on paper, but it adjusts like an 8-hour westward shift (16 − 24 = −8). If the calculator shows a difference over 12 hours, subtract 24 to get the effective shift and its real direction; the direction and recovery figures assume the difference you enter. Very long trips also cross the International Date Line, so double-check the arrival date on your ticket.