Timezone Converter — Free World Time Zone Converter
Missing meetings because of timezone confusion? Trying to schedule a call across continents? Our free online timezone converter instantly converts any date and time between all major world timezones — including automatic DST (Daylight Saving Time) adjustments, UTC offsets, and “Use Current Time” to convert right now.
What Is a Timezone Converter?
A timezone converter is a tool that translates a point in time from one timezone to another. The Earth is divided into 24 primary timezone regions (plus dozens of partial-hour offsets), each offset from Coordinated Universal Time (UTC) by a specific number of hours and minutes.
Without a converter, calculating timezone differences requires knowing:
- The UTC offset of the source timezone (e.g., IST = UTC+5:30)
- The UTC offset of the target timezone (e.g., PST = UTC−8:00)
- Whether Daylight Saving Time is currently active (which shifts the offset by +1 hour for many regions)
Our converter handles all of this automatically using the browser’s built-in Intl.DateTimeFormat API, which has IANA timezone database support built in — the same authoritative timezone data used by operating systems worldwide.
How to Use the Timezone Converter
- Select or enter a date and time in the “Date & Time” field. Click Use Current Time to auto-fill with the current moment.
- Choose the source timezone — the timezone that your input date/time belongs to.
- Choose the target timezone — the timezone you want to convert to.
- Click Convert Time.
- The output shows the converted date and time, the full timezone name, and the UTC offset.
Change either dropdown to instantly re-convert without clicking again.
Supported Timezones
Our converter supports all major IANA timezones across all inhabited continents:
| Region | Timezone | UTC Offset |
|---|---|---|
| Americas | America/New_York | UTC−5 / UTC−4 (EDT) |
| America/Chicago | UTC−6 / UTC−5 (CDT) | |
| America/Denver | UTC−7 / UTC−6 (MDT) | |
| America/Los_Angeles | UTC−8 / UTC−7 (PDT) | |
| America/Sao_Paulo | UTC−3 | |
| Europe | Europe/London | UTC+0 / UTC+1 (BST) |
| Europe/Paris | UTC+1 / UTC+2 (CEST) | |
| Europe/Moscow | UTC+3 | |
| Asia | Asia/Dubai | UTC+4 |
| Asia/Kolkata | UTC+5:30 | |
| Asia/Singapore | UTC+8 | |
| Asia/Tokyo | UTC+9 | |
| Asia/Shanghai | UTC+8 | |
| Oceania | Australia/Sydney | UTC+10 / UTC+11 (AEDT) |
| Pacific/Auckland | UTC+12 / UTC+13 (NZDT) |
Understanding UTC and Timezone Offsets
UTC (Coordinated Universal Time) is the primary time standard by which the world regulates clocks and time. It is not adjusted for daylight saving time and does not change across seasons. All other timezones are defined as an offset from UTC:
UTC+5:30— India Standard Time is 5 hours and 30 minutes ahead of UTCUTC−8— Pacific Standard Time is 8 hours behind UTCUTC+0— Greenwich Mean Time (winter) matches UTC exactly
The key formula: Target Time = Source Time − Source UTC Offset + Target UTC Offset
Example: Converting 3:00 PM IST (UTC+5:30) to EST (UTC−5):
- 3:00 PM − 5:30 = 9:30 AM UTC
- 9:30 AM − 5:00 = 4:30 AM EST
Daylight Saving Time (DST)
DST is the practice of advancing clocks by one hour during summer months to extend evening daylight. It is observed by most of North America, Europe, and parts of other regions — but not by countries including India, China, Japan, Saudi Arabia, Iceland, or most of Africa.
DST dates vary by country:
| Region | DST Start | DST End |
|---|---|---|
| United States / Canada | Second Sunday in March | First Sunday in November |
| European Union | Last Sunday in March | Last Sunday in October |
| Australia | First Sunday in October | First Sunday in April |
Our converter uses the IANA timezone database, which has all historical and current DST rules built in. You never need to manually adjust for DST.
Common Use Cases
- Scheduling international meetings — Find when 10 AM New York is in London, Tokyo, and Sydney simultaneously
- Remote team coordination — Display working hours of team members in different countries
- International flight planning — Decode departure and arrival times across timezone changes
- Financial markets — Stock exchange opening times (NYSE = EST, LSE = GMT, TSE = JST)
- Live event watching — Converting a game or webinar start time to your local timezone
- API timestamp interpretation — Convert UTC timestamps from server logs to local time
Frequently Asked Questions
Does the converter account for Daylight Saving Time automatically?
Yes. The converter uses the Intl.DateTimeFormat API with IANA timezone identifiers. DST is automatically applied based on the specific date you enter. For example, if you enter a July date for America/New_York, the tool will use EDT (UTC−4), not EST (UTC−5).
What is the difference between GMT and UTC?
GMT (Greenwich Mean Time) and UTC (Coordinated Universal Time) are functionally equivalent for most practical purposes. UTC is the official scientific standard, maintained by atomic clocks. GMT is a civil timezone (used by the UK in winter). They differ by less than 1 second.
Can I convert times for dates in the past or future?
Yes. The datetime input field allows any date, past or future. Historical DST rules are stored in the IANA database, so past conversions use the DST rules that were in effect at that time.
How do I know if 9 AM EST and 9 AM EDT are the same?
No — they differ by one hour. EST (Eastern Standard Time) is UTC−5. EDT (Eastern Daylight Time) is UTC−4. During summer (March–November), New York uses EDT. During winter, it uses EST. The tool automatically determines which applies based on the date.
What does “Use Current Time” do?
It fills the date/time input with the current local time of your browser. You can then convert it to any other timezone to see what time it is there right now.
Why are some country names not listed as timezones?
Timezones are not mapped 1:1 with countries. A large country like the United States has multiple timezones (ET, CT, MT, PT). The IANA timezone database uses geographic zone names (like America/New_York) rather than country names to avoid ambiguity.
