Time Difference Calculator | Timezone Converter (Free)
Calculate the time difference between any two timezones worldwide and convert date and time instantly — 100% free with no sign-up required. Powered by the IANA time zone database, daylight saving time is applied automatically, making it easy to schedule international meetings, calls, and travel.
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What Is Timezone Conversion?
Local time around the world is defined as an offset from UTC (Coordinated Universal Time), but the math is rarely a simple addition. Some countries use 30- or 45-minute offsets instead of whole hours, and regions that observe daylight saving time shift the offset itself depending on the time of year. This tool takes the city (or timezone) and date/time you specify for both sides of the conversion and works out the correct local time, accounting for all of this.
Conversions are powered by the IANA time zone database, so daylight saving transitions are applied automatically based on the date you enter. When scheduling a meeting far in advance, whether that date falls inside a daylight saving period can shift the result by an hour, so always enter the actual date of the event rather than today's date.
How to Convert Between Timezones
- Set the source timezone and date/time Enter the region you want to use as your reference and the date/time in that region. If you're sharing your own schedule, choose your own timezone here.
- Choose the destination timezone Select the other party's region. Since some countries span multiple timezones, check the specific city rather than just the country name.
- Check the converted result The date and time in the destination timezone is displayed. Conversions can cross into the previous or next day, so confirm the date as well as the time.
Tips for getting more out of it
- Using UTC (Coordinated Universal Time) as your reference reduces timezone conversion errors. Japan Standard Time (JST) is UTC+9 with no daylight saving.
- Daylight saving time is handled automatically for countries that observe it (e.g. US, Europe).
- When scheduling meetings with a global team, enter the other party's timezone to convert to your local time.
- Common timezones:
America/New_York(UTC−5/−4),Europe/London(UTC+0/+1),Asia/Shanghai(UTC+8)
When to Use a Timezone Converter
Scheduling an international meeting
Check whether the other party's local time falls within reasonable business hours. This matters especially for recurring meetings that span a daylight saving transition.
Checking a deadline or release time
When an overseas service states a deadline in UTC or its own local time, you can work out exactly what that means in Japan Standard Time or your own zone.
Planning a trip itinerary
Lining up departure and arrival times lets you plan what to do after landing in local time — especially useful for long-haul flights that cross into a different date.
Reaching out to family or friends abroad
Check whether the other person is likely to be awake before you call or message, so you don't end up waking them in the middle of the night.
Timezone Terms
- UTC
- Coordinated Universal Time — the global reference point that every region's local time is expressed as an offset from.
- Offset
- How far a timezone sits from UTC. Japan is UTC+9, but some regions — such as India at UTC+5:30 — use 30-minute increments instead of whole hours.
- Daylight Saving Time (DST)
- A system where clocks move forward by one hour for part of the year to make better use of daylight. Countries that observe it change their offset twice a year.
- IANA Time Zone Database
- The standard reference dataset of the world's timezone rules, identified by region/city names such as
Asia/Tokyo. - International Date Line
- An imaginary boundary running through the Pacific Ocean. Crossing it shifts the calendar date by one day.
FAQ
America/New_York) rather than a fixed offset like UTC-5.Asia/Tokyo (JST) is a named timezone with full historical DST data, while UTC+9 is a fixed offset with no DST rules. For meeting scheduling, using Asia/Tokyo is recommended.en.wikipedia.org/wiki/List_of_tz_database_time_zones.
Side Note — The World's Unusual Timezones — Countries with 30- and 45-Minute Offsets
There are over 400 timezones in the world. India uses UTC+5:30 (30-minute offset) and Nepal uses UTC+5:45 (45-minute offset), both non-integer-hour timezones. South Australia and the Northern Territory of Australia also use UTC+9:30, putting them 30 minutes behind neighboring Queensland (UTC+10).
China spans 5,200 km east to west, which should put it across five timezones, yet the entire country is unified under UTC+8 (Beijing Time). As a result, in the far western Xinjiang Uyghur Autonomous Region, the sun rises at around 8–9 a.m. local time in summer, and many residents are said to use an unofficial local timezone in practice.
Samoa ended Thursday, December 29, 2011, and moved the following day directly to Saturday, December 31 (crossing the International Date Line), creating a week that literally had no Thursday. The move was made to better align business dealings with Australia and New Zealand.