This time zone converter changes a date and time from one time zone to another and shows the same moment in major cities around the world. Daylight saving time is applied automatically for the date you choose, so it works for meetings, calls and flights at any time of year.
How time zones work
Every time zone is defined as an offset from Coordinated Universal Time (UTC). New York is UTC−5 in winter and UTC−4 in summer; London is UTC+0 in winter and UTC+1 in summer. To convert, the calculator turns your time into UTC, then applies the offset of the target zone on that exact date.
Daylight saving time dates
| Region | Clocks go forward | Clocks go back |
|---|---|---|
| US and Canada | Second Sunday in March | First Sunday in November |
| UK and EU | Last Sunday in March | Last Sunday in October |
| Australia (NSW, Victoria, SA, Tasmania, ACT) | First Sunday in October | First Sunday in April |
| New Zealand | Last Sunday in September | First Sunday in April |
Arizona (except the Navajo Nation), Hawaii, Queensland, Western Australia and the Northern Territory do not use daylight saving time. For a few weeks each spring and autumn, the gap between the US and Europe is one hour shorter than usual because they change on different dates.
Worked example
A call at 9:00 AM on Monday 12 October 2026 in New York (UTC−4) is 2:00 PM in London (UTC+1) and midnight at the start of Tuesday 13 October in Sydney (UTC+11), because Australia moved its clocks forward on 4 October.
Frequently asked questions
What is the time difference between New York and London?
Usually 5 hours, with London ahead. For a few weeks in March and in late October to early November it is 4 hours, because the US and UK change their clocks on different dates.
What is the time difference between London and Sydney?
It varies from 9 to 11 hours through the year, because the UK and Australia have daylight saving time in opposite seasons.
What is UTC?
Coordinated Universal Time, the world’s time standard. It does not change for daylight saving time, so it is used for aviation, computing and scheduling across zones.
Is GMT the same as UTC?
For everyday purposes, yes. GMT is the UK’s winter time zone and is effectively equal to UTC; in summer the UK uses British Summer Time (UTC+1).
Why does the calculator say a time does not exist?
When clocks go forward, an hour is skipped, for example 2:30 AM on the US spring change date. The calculator uses the nearest valid time.
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Sources
Last reviewed: October 2026.