Home / Everyday / Time Zone Converter

Time Zone Converter

Choose a date and a time in one zone and see what the clock reads in another. The result accounts for daylight saving on that exact date, flags times that do not exist or happen twice, and lists the same moment in 36 zones.

By Adzita Editorial Team · Updated 2026-11-03 · How we build and check our tools

How a conversion works

Every zone is defined by an offset from Coordinated Universal Time (UTC). Karachi is UTC+5 all year, Kolkata is UTC+5:30, and Tokyo is UTC+9. To convert, the calculator first turns the source clock time into a single universal instant by subtracting the source offset, then adds the destination offset to that instant to read the clock there.

Destination time = source time − source offset + destination offset

Because offsets can change during the year, the offset has to be looked up for the exact date, not assumed. The tool asks the browser's built-in time zone database, which follows the IANA tz database, for the offset of each zone at that instant. That is why the same two cities can be four, five or six hours apart depending on the date.

Daylight saving time and its two awkward cases

Many regions move their clocks forward in spring and back in autumn, and the change dates differ by country. For a few weeks each year the gap between two cities therefore changes, usually because one country has switched and the other has not. Always convert using the date of the event, not today's date.

• The skipped hour. When clocks jump forward, a stretch of local time never happens. 02:30 on the spring change day in New York is one example in 2026. The tool warns you and uses the first valid time after the jump.
• The repeated hour. When clocks fall back, a stretch of local time occurs twice. The tool warns you and uses the earlier of the two.

Schedule important meetings away from the change hours, or write the time in UTC as well.

Planning meetings across zones

The table under the result lists the same moment in 36 zones, which helps when a group spans several continents. Look for a window that falls inside ordinary waking hours for everyone, and note the date column: a late evening in one place can be the next morning in another.

Some zones are not whole hours from UTC, including India at +5:30 and several others at +5:45 or +8:45 that are not listed here. Never convert by adding a rounded number of hours. Also remember that governments change zone rules, sometimes with short notice, so a browser or operating system that is out of date may give an old answer for a future date.

Abbreviations such as IST, CST or BST are ambiguous, since each is used by more than one region. Use the city names in the lists instead.

Limits of this tool

The list is a curated set of widely used zones rather than every zone in the database. Dates are limited to 1970 through 2100, and results for future dates assume current rules still apply then. Time input is taken as a wall-clock time in the source zone, not as a duration. For differences between two dates rather than two places, the time calculator and the date tools on this site are the better fit.

Worked example

A call is set for noon in New York on 20 March 2026. The United States has already moved to daylight time on that date but the United Kingdom has not, so the gap is four hours rather than the usual five.

Inputs

Result

Accuracy note: Results are calculated in your browser from the values you enter. Check anything that matters for legal, academic or financial purposes against the official source.

Frequently asked questions

Related calculators