Time Zone Converter & Calculator

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Convert a date and time from one timezone to another, worldwide. Easily convert time zones internationally using this time zone calculator with daylight saving adjustments (DST) a.k.a. international clock converter. For example, convert a time in EST to PST, or EST to GMT for scheduling business meetings, video conferences, events, and more across time zones within the US and around the world.

Quick navigation:

Time zone basicsUsing the time zone converterUS time zone mapMap of time zones in the WorldTime difference and Daylight Savings Time (DST)

Time zone basics

The world is split into 38 time zones[1][2], some shared by multiple countries with hundreds of millions of people in them while others are only used in a couple of remote locations where barely anyone lives. More in "How many time zones there are". A time zone is defined by the territory which falls in it and its offset relative to UTC (Coordinated Universal Time). UTC is a widely accepted time standard that measures the time at 0° longitude by doing a weighted average measurement of hundreds of atomic clocks around the world [3].

The offset is how many hours and minutes the time zone's clock is relative to UTC [4]. For example, Eastern Standard Time is UTC-05:00 while Pacific Standard Time is UTC-08:00, meaning that EST time is lagging UTC by five hours whereas PST is lagging by eight hours. So if UTC is 20:00 (8:00 PM), EST would be 15:00 (3:00 PM) whereas PST would still be 12:00 (noon). While it is commonly thought that each timezone is offset by one hour from its neighboring zones, in fact there are timezones with half-hour or even quarter-hour offsets, which is why there are 38 international time zones and not 24.

Using the time zone converter

To convert between time zones, begin by entering a full date for the location you want to compute the time zone difference from, including the year (YYYY, e.g. 2026), month, and day. You can then enter the hour, minute, and second in 24-hour format. Leaving either of these empty is optional, and would be treated the same as entering zeroes: 00:00:00. This corresponds to 12:00 AM on the specified date.

Proceed to choose what time zone this time is from and then select what time zone to convert it to. You may refer to the time zone maps below for reference while using the world clock converter. If a place observes DST our time zone converter will take daylight saving into account automatically if "Adjust for DST" is set to "Yes". Otherwise it is on you to make sure to use the correct timezone depending on whether daylight saving is in effect or not. The time converted to the specified time zone is displayed automatically as you type and change time zone selections, and is displayed according to your browser preference, as well as in 24 hour format.

For example, to convert Eastern Time to GMT, enter the date and time, select "UTC-5 Eastern Time" in the "From" drop-down, then select "UTC+0 (GMT)" in the "To" drop-down, and the resulting date and time in GMT will be displayed in the results fields.

US time zone map

The USA spans a lot of the Earth's surface longitudinally so it uses a total of nine time zones across its territory. The most used are Eastern Time (ET), Central Time (CT), Mountain Time (MT), and Pacific Time (PT). The standard UTC offsets are denoted EST, CST, MST, and PST, whereas the time zone offsets during DST (Daylight Saving Time) are denoted EDT, CDT, MDT, and PDT.

The other time zones in the United States are the Atlantic, Alaska, Hawaii-Aleutian, Samoa, and Chamorro. Note that while most US time zones observe DST, the Atlantic, Samoa, and Chamorro Time Zones do not.

Using our international clock converter, you can calculate meeting times, event times and more across the entire world.

Map of time zones in the World

The map displays all 38 standard time zones across the world and is current as of early-2026 and the International Dateline. Click the map image to enlarge it in a new tab, then zoom in further as necessary.

Time difference and Daylight Savings Time (DST)

While the time difference between any two standard time zones is always the same, certain countries or states may switch time zones while observing daylight saving (DST), making the calculations to convert time zones internationally more difficult. Most countries that observe daylight saving are in North America (most of the US and Canada, Cuba), Europe (the vast majority of European countries follow DST), New Zealand, and some Australian states. The only Asian country to have DST is Israel while the only country in Africa to still use DST is Egypt. Our time zone calculator supports both taking DST into account and raw UTC zone math in case you want to take care of the daylight saving and select the appropriate UTC zones yourself.

In practice, DST means that a country switches from one UTC time zone to another twice a year, typically in spring and autumn. For example, in Standard Time New York would be in the UTC+5:00 zone, for approximately half of the year during and around summer, New York would shift its time to the UTC+4:00 zone. Since most of the rest of the US will also switch time zones at the same time, the time difference between New York and Los Angeles would remain the same throughout the year. You should keep this in mind when using a time zone converter.

The issue is when performing time zone calculations relative to a non-DST adhering location. The difference between that location and New York would differ by one hour in one half of the year versus the other. Care should be taken even when doing time zone conversion between two places that observe DST since different jurisdictions might have slightly different rules as to when DST goes into effect and when it ends. For example, it is not uncommon for European countries to switch to their respective DST time zone while the US or Australia may do that a week or two later (or earlier).

Common time zone conversions

Below is a list of common time zone conversions performed when organizing meetings, travel plans, and others. You can use the table as a quick reference, instead of the time zone calculator above. For example, if you are wondering something like "3PM cst is what time est?", then just look up the conversion table to see what time is it in EST when it is 3PM CST.

times at different time zonesNew York (EST)11 AM12 PM13 PM14 PM15 PM16 PM17 PMChicago (CST)Denver (MST)L.A. (PST)London (GMT)Paris (CET)BeijingTokyo10 AM9 AM8 AM4 PM5 PM12 AM1 AM11 AM10 AM9 AM5 PM6 PM1 AM2 AM12 AM11 AM10 AM6 PM7 PM2 AM3 AM13 AM12 AM11 AM7 PM8 PM3 AM4 AM14 PM13 PM12 PM8 PM9 PM4 AM5 AM15 PM14 PM13 PM9 PM10 PM5 AM6 AM16 PM15 PM14 PM10 PM11 PM6 AM7 AM

The above table assumes all times are in standard time and daylight saving is not in effect in any of these locations.

References

1 IANA (2026) "Time Zone Database", online at https://www.iana.org/time-zones, accessed on Jan 26, 2026

2 Wikipedia (2026) "Time zone", online at https://en.wikipedia.org/wiki/Time_zone, accessed on Jan 26, 2026

3 International Bureau of Weights and Measures (2020) "BIPM Annual Report on Time Activities" Vol. 15. p. 9. ISBN 978-92-822-2280-5

4 ISO: "ISO 8601-1:2019 — Date and time"

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