Time Zone Converter
Enter a date and time in one time zone to see the matching local time in up to four other cities, with each UTC offset and whether the day changes.
このコンテンツは英語です。
| Place | Local time | Offset | Day |
|---|
計算例
London to New York in October
10:00 on 15 October 2026 in London, shown in New York
05:00 on 15 October 2026 in New York.
New York is five hours behind London on this date, because the UK is on summer time and the US has not yet changed its clocks.
London to New York in January
10:00 on 15 January 2027 in London, shown in New York
05:00 on 15 January 2027 in New York.
In winter both cities use standard time, so the gap is still five hours, but the rules are looked up for the date entered.
Time Zone Converter について
A time zone converter shows what time it is in other cities when you know the time in one place. Enter a date and time, choose the city where it is happening, then pick up to four other cities to compare. The calculator works out the local time in each one, shows the UTC offset that applies on that date and says whether the day changes. It is handy for arranging calls with colleagues, catching a flight or watching a live event abroad.
Offsets change through the year in places that move their clocks forward and back, such as the UK, most of Europe, the United States and Australia. The calculator uses the rules in force on the date you enter, so a meeting in late October can give a different answer from the same time in January. Some cities, such as Mumbai and Kathmandu, sit half or quarter hours away from UTC, and these are shown with their minutes. If a time does not exist because the clocks have moved forward, you are told and shown the first valid time.
Time Zone Converter の使い方
- Enter the date and time in the starting city.
- Pick up to four cities to compare, leaving unused boxes on Not used.
- Read the local time, UTC offset and day column for each place.
- Use the current time button to start from the moment you are in.
主な使いみち
- Scheduling a video call with colleagues in several countries
- Checking the local time before calling family abroad
- Working out when a live broadcast or match starts in your own time zone
- Planning travel across time zones so you know the arrival time
よくあるご質問
What is a UTC offset?
A UTC offset is the difference between a local time and Coordinated Universal Time, the reference standard that clocks around the world are measured from. Offsets are written as UTC plus or minus a number of hours, with minutes where they apply. Tokyo is UTC+9 all year. Sydney is UTC+11 from early October, when daylight saving starts, and UTC+10 in the winter months.
Why does the time difference change during the year?
Many places move their clocks forward in spring and back in autumn, which changes their offset by an hour. Places that do not use daylight saving keep the same offset all year. The gap between London and New York is usually five hours, but it is four for a few weeks in spring and autumn, when the two countries change their clocks on different dates. The calculator uses the date you enter, so it picks up the offsets that applied then.
How do I convert a time from one time zone to another?
Start from the UTC offset of the place you know, subtract it to reach UTC, then add the offset of the place you want. For example, 9:00 in London in October, when the offset is UTC+1, is 8:00 UTC. That is 4:00 in New York in October, when the offset is UTC-4. The calculator does this automatically for up to four places, so you do not need to work out each step yourself.
Why does a time sometimes not exist?
When clocks go forward in spring, one hour is skipped. In the UK that is the hour between 1 and 2 in the morning, so a time such as 1:30 does not occur that day. The calculator shows the first valid time after the change and says so. When clocks go back, one hour is repeated, so check the time with the other person if a meeting falls in that repeated hour.
Is the time zone converter accurate for future dates?
The results follow the time zone rules currently in force for each city, so they are reliable for dates in the near future. Governments can change their clock rules at short notice, and that can alter results for dates a long way ahead. For an important booking or flight, check the time with the service you are using and confirm it with the person you are meeting.