What is a time zone converter?

A time zone converter changes a date and time from one time zone into another, such as London time to New York time.

How do I convert time between two cities?

Choose the source date, time, and city time zone, then choose the destination time zone. The converter maps the source time to UTC and displays the same instant in the destination zone.

UTC is Coordinated Universal Time. It is the global reference time standard used for aviation, computing, logs, and international coordination.

What is a UTC offset?

A UTC offset shows how far a time zone is ahead of or behind UTC, such as UTC+01:00 or UTC-05:00.

What is an IANA time zone?

An IANA time zone is a named time zone such as Europe/London or America/New_York. These names can account for daylight saving rules.

Why do time differences change during the year?

Some regions observe daylight saving time while others do not, and DST dates vary by country. That can temporarily change the time difference between cities.

What is daylight saving time?

Daylight saving time is a seasonal clock change used in some regions, usually shifting clocks forward in spring and back in autumn.

Why are time zone abbreviations confusing?

Abbreviations such as CST, IST, and EST can refer to different zones in different countries. City-based IANA time zones are safer.

Can the converted date be different?

Yes. A time zone conversion can land on the previous day, same day, or next day depending on the time difference.

Is this converter accurate for future dates?

The converter uses browser-native IANA time zone rules. Future accuracy depends on the time zone data available in the user's browser and any future government rule changes.

Time Zone Converter | World Time and City Time Converter

Time Zone Converter

Choose the source time zone and destination time zone. City-based zones help account for daylight saving changes.

Date

Time

From time zone

To time zone

Converted date and time

3:38 am

Wed, 17 Jun 2026

8:38 am London, United Kingdom = 3:38 am New York, United States

Source time

Wed, 17 Jun 2026, 8:38 am

Converted time

Wed, 17 Jun 2026, 3:38 am

Source time zone

London, United Kingdom

Destination time zone

New York, United States

Source UTC offset

UTC+01:00

Destination UTC offset

UTC-04:00

Time difference

-5.00 hours

Day difference

Same calendar day

Destination DST status

Likely daylight saving time

IANA time zones

Uses city-based time zones such as Europe/London and America/New_York.

DST-aware method

Offsets are calculated for the selected date and time using browser Intl rules.

Scheduling friendly

Shows date changes, UTC offsets, and whether the result is within typical work hours.

Dynamic Time Insights

The converted time is same calendar day in New York, United States.

The destination time is classified as outside typical business hours.

Using city-based time zones helps account for daylight saving changes.

UTC is a stable reference time and does not observe daylight saving time.

London, United Kingdom is UTC+01:00 on the selected date.

New York, United States is UTC-04:00 on the selected date.

How Time Zone Conversion Works

Start with local time

The selected date and time are interpreted inside the source time zone.

Map to UTC

That local time is converted into one UTC timestamp, representing the real instant.

Format destination

The same UTC instant is displayed in the destination time zone.

Compare dates

The converted time can fall on the same day, previous day, or next day.

UTC Offsets and IANA Time Zones

UTC offsets

UTC offsets show how far a zone is ahead of or behind UTC, such as UTC+01:00 or UTC-05:00. Offsets can change with daylight saving time.

IANA time zones

IANA names such as Europe/London and America/New_York identify real regions and can account for daylight saving rules.

Avoid ambiguous abbreviations

Abbreviations such as CST, IST, and EST can mean different things in different countries.

City-based conversion

City and region names are safer than fixed offsets when you need date-specific accuracy.

Daylight Saving Time Explained

Seasonal shifts

Some regions move clocks forward or back during part of the year.

Not universal

Not every country or region observes daylight saving time.

Dates vary

DST start and end dates can vary by country and may change over time.

Time gaps shift

The time difference between two cities can change when one region observes DST and another does not.

Use IANA zones

IANA time zones are better than fixed UTC offsets for DST-sensitive dates.

Browser data matters

This tool relies on the time zone rules available in the user's browser.

Scheduling Across Time Zones

Check the date

Always check whether the converted time lands on the previous, same, or next calendar day.

Avoid awkward hours

Late-night or early-morning conversions may be unsuitable for meetings.

Include time zone names

Use clear city or IANA time zone names in calendar invites.

Use UTC for logs

UTC is useful for technical logs, global coordination, and systems work.

Double-check DST weeks

Meetings around DST changes are more likely to shift unexpectedly.

Confirm work hours

Working hours vary by region, culture, company, and individual schedule.

Common Time Zone Examples

London to New York often differs by about 5 hours, but daylight saving timing can shift the gap.

New York to Los Angeles is usually a 3-hour difference.

London to Dubai is commonly 3 or 4 hours depending on the selected date.

London to India is commonly 4.5 or 5.5 hours depending on UK daylight saving time.

London to Singapore is commonly 7 or 8 hours depending on the selected date.

London to Sydney can vary because both regions may change clocks at different times.

UTC is a stable reference and does not observe daylight saving time.

US Pacific time may appear as PST or PDT depending on daylight saving time.

Formula and Method Explanation

UTC Time = Local Time − UTC Offset

Converted Local Time = UTC Time + Destination UTC Offset

Step 1: parse the selected local date and time in the source time zone

Step 2: convert that local time into a UTC timestamp

Step 3: format the UTC timestamp in the destination time zone

Step 4: compare offsets to show time difference and day change

The simplified offset formula works only when the correct date-specific offsets are known. This page uses browser-native Intl APIs and IANA time zone names so daylight saving changes can be reflected where supported.

Practical Use Cases

Remote team meetings

International travel planning

Flight and hotel coordination

Client calls across countries

Webinar scheduling

Server logs and UTC timestamps

Online classes

Family calls abroad

Market opening checks

Frequently Asked Questions

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