How do I convert time between different time zones?

Select your source timezone and enter the date and time you want to convert. Then select the target timezone. The converter instantly shows the equivalent date and time in the target timezone, accounting for UTC offsets and daylight saving time differences.

What is UTC and how does it relate to other time zones?

UTC (Coordinated Universal Time) is the primary time standard by which the world regulates clocks. All other time zones are expressed as offsets from UTC. For example, EST is UTC-5, IST is UTC+5:30, and JST is UTC+9. UTC does not observe daylight saving time.

Does this converter account for daylight saving time?

Yes. Our converter uses the browser's built-in Intl.DateTimeFormat API which automatically accounts for daylight saving time (DST) transitions. The conversion reflects the correct offset for the specific date you enter, including DST adjustments.

What is the difference between GMT and UTC?

GMT (Greenwich Mean Time) and UTC (Coordinated Universal Time) are often used interchangeably in practice, as they share the same current time. However, GMT is a time zone while UTC is a time standard. UTC is defined by atomic clocks and is the basis for civil timekeeping worldwide.

How many time zones are there in the world?

There are 24 standard time zones, each roughly 15 degrees of longitude wide. However, many regions use offsets that differ by 30 or 45 minutes (like India at UTC+5:30 or Nepal at UTC+5:45), bringing the practical total to over 38 distinct UTC offsets in use today.

Timezone Converter

Compare time across multiple cities with live clocks, DST detection & meeting planner

40+ timezones | DST-aware | Meeting finder

Convert a specific date & time

Quick-add a city

Timezone Slots (/5)

Meeting Time Finder

All in hours (8–18) Some in hours None in hours

Each column = one UTC hour of the day. Colour shows business-hours overlap for all your added zones.

Overlap

DST Status

UTC Offsets

Pro Tip

Add up to 5 cities using the presets or dropdown. Use the date-time picker to compare a future meeting time. The green cells in the Meeting Finder show hours that work for everyone.

Understanding Time Zones

How the world keeps track of time across different regions

Time zones were established in the late 19th century to standardize timekeeping across regions. Before time zones, each city set its clocks based on the local solar noon, creating confusion for railways and telegraph communications. Today, the world is divided into 24 standard time zones, each offset from Coordinated Universal Time (UTC).

UTC serves as the global time standard and does not observe daylight saving time. All other time zones are expressed as positive or negative offsets from UTC. Some regions use non-standard offsets such as UTC+5:30 (India) or UTC+5:45 (Nepal), and many countries shift their clocks forward or backward seasonally for Daylight Saving Time (DST).

UTC Standard

Coordinated Universal Time (UTC) is the primary time standard used worldwide. It replaced GMT as the international civil time standard and is maintained by a network of atomic clocks around the globe.

Daylight Saving Time

Many countries adjust clocks forward by one hour in spring and back in autumn. Not all regions observe DST, and the start/end dates vary by country, making timezone conversions date-dependent.

IANA Timezone Database

The IANA Time Zone Database (also called tz or zoneinfo) contains the history of local time for many locations. Identifiers like "America/New_York" capture both the offset and DST rules for each region.

Common Timezone Abbreviations

Quick reference for frequently used timezone codes and their UTC offsets

Abbreviation	Full Name	UTC Offset	Major Cities
UTC	Coordinated Universal Time	+00:00	Reykjavik
GMT	Greenwich Mean Time	+00:00	London (winter), Dublin, Lisbon
EST	Eastern Standard Time	-05:00	New York, Toronto, Miami
EDT	Eastern Daylight Time	-04:00	New York, Toronto (summer)
CST	Central Standard Time	-06:00	Chicago, Houston, Mexico City
MST	Mountain Standard Time	-07:00	Denver, Phoenix, Salt Lake City
PST	Pacific Standard Time	-08:00	Los Angeles, San Francisco, Seattle
PDT	Pacific Daylight Time	-07:00	Los Angeles, Seattle (summer)
AKST	Alaska Standard Time	-09:00	Anchorage, Juneau
HST	Hawaii Standard Time	-10:00	Honolulu
CET	Central European Time	+01:00	Paris, Berlin, Rome, Madrid
EET	Eastern European Time	+02:00	Cairo, Athens, Helsinki
MSK	Moscow Standard Time	+03:00	Moscow, St. Petersburg
IST	India Standard Time	+05:30	Mumbai, Delhi, Bangalore
CST (China)	China Standard Time	+08:00	Beijing, Shanghai, Hong Kong
JST	Japan Standard Time	+09:00	Tokyo, Osaka
KST	Korea Standard Time	+09:00	Seoul, Busan
AEST	Australian Eastern Standard Time	+10:00	Sydney, Melbourne
NZST	New Zealand Standard Time	+12:00	Auckland, Wellington

Frequently Asked Questions

Common questions about time zones and conversions

Select your source timezone and enter the date and time you want to convert. Then choose the target timezone from the dropdown. The converter instantly shows the equivalent date and time, including any date changes that occur when crossing the International Date Line or midnight boundaries.

UTC (Coordinated Universal Time) is the primary time standard by which the world regulates clocks and time. All time zones are defined as offsets from UTC. For example, EST (Eastern Standard Time) is UTC−5, meaning it is 5 hours behind UTC. IST (India Standard Time) is UTC+5:30, meaning it is 5 hours and 30 minutes ahead of UTC.

Yes. The converter uses the browser's built-in Intl.DateTimeFormat API, which references the IANA Time Zone Database. This means conversions automatically reflect DST transitions for the specific date you enter. For example, converting from New York time in July uses EDT (UTC−4), while the same conversion in January uses EST (UTC−5).

GMT (Greenwich Mean Time) is a time zone originally based on mean solar time at the Royal Observatory in Greenwich, London. UTC is a time standard maintained by atomic clocks. In practice, GMT and UTC share the same time (UTC+0), but UTC is the standard used for international timekeeping, aviation, and computing.

While there are 24 standard hourly time zones, the actual number of unique UTC offsets in use is over 38. This is because some regions use half-hour (UTC+5:30 for India, UTC+9:30 for Central Australia) or quarter-hour offsets (UTC+5:45 for Nepal, UTC+12:45 for Chatham Islands). Additionally, DST creates seasonal variations.

Standard time zones are spaced at one-hour intervals, but some countries chose offsets that better align with their solar noon. India uses UTC+5:30 as a compromise for its wide east-west span. Nepal uses UTC+5:45 to distinguish itself from India. Iran uses UTC+3:30 for historical and geographic reasons.