Time Zone Calculator
Convert time between different time zones, see current times around the world, and calculate time differences. Perfect for scheduling international meetings, planning travel, and staying connected across time zones.
Understanding Time Zones
A time zone is a region of the globe that observes a uniform standard time for legal, commercial, and social purposes. Time zones are defined by their offset from UTC (Coordinated Universal Time), the primary time standard by which the world regulates clocks and time.
This calculator supports three modes:
- Convert Time: Convert a specific time from one time zone to another.
- World Clock: See the current time in multiple time zones simultaneously.
- Time Difference: Calculate the time difference between two time zones.
How Does the Time Zone Calculator Work?
The calculator uses the standard UTC offset for each time zone:
UTC Offsets (Standard):
UTC: ±0:00 • GMT: ±0:00 • EST: -5:00 • CST: -6:00 • MST: -7:00 • PST: -8:00
CET: +1:00 • EET: +2:00 • MSK: +3:00 • IST: +5:30 • JST: +9:00
AEST: +10:00 • NZST: +12:00 • HST: -10:00
Daylight Saving Time (DST) offsets may vary by season.
For conversions, the calculator:
- Converts the input time to UTC using the source time zone's offset.
- Converts from UTC to the target time zone using its offset.
- Adjusts for Daylight Saving Time where applicable.
Time Zone Reference Table
| Time Zone | UTC Offset | DST Offset | Region |
|---|---|---|---|
| UTC | ±0:00 | — | Global |
| GMT | ±0:00 | — | UK, Africa |
| EST / EDT | -5:00 | -4:00 | US East Coast |
| CST / CDT | -6:00 | -5:00 | US Central |
| MST / MDT | -7:00 | -6:00 | US Mountain |
| PST / PDT | -8:00 | -7:00 | US West Coast |
| AKST / AKDT | -9:00 | -8:00 | Alaska |
| HST | -10:00 | — | Hawaii |
| BST | +1:00 | — | UK (Summer) |
| CET / CEST | +1:00 | +2:00 | Central Europe |
| EET / EEST | +2:00 | +3:00 | Eastern Europe |
| MSK | +3:00 | — | Moscow |
| IST | +5:30 | — | India |
| JST | +9:00 | — | Japan |
| AEST / AEDT | +10:00 | +11:00 | Australia East |
| NZST / NZDT | +12:00 | +13:00 | New Zealand |
Daylight Saving Time (DST) Notes
- US & Canada: DST starts second Sunday in March, ends first Sunday in November.
- Europe: DST starts last Sunday in March, ends last Sunday in October.
- Australia: DST starts first Sunday in October, ends first Sunday in April.
- UK: BST (British Summer Time) is GMT+1 from March to October.
- Hawaii & Arizona: Most areas do not observe DST.
❓ Time Zone Calculator FAQ
What is a time zone?
A time zone is a region that observes a uniform standard time. Time zones are defined by their offset from UTC (Coordinated Universal Time).
What is UTC?
UTC (Coordinated Universal Time) is the primary time standard by which the world regulates clocks and time. It is the successor to GMT and is used as the basis for all time zones.
What is the difference between UTC and GMT?
UTC and GMT are often used interchangeably. GMT (Greenwich Mean Time) is a time zone used in the UK and parts of Africa. UTC is a time standard used globally. They are functionally equivalent for most purposes.
How do I convert time between time zones?
Use the "Convert Time" mode. Enter the time, select the source time zone and the target time zone, then click "Calculate." The calculator will show the converted time.
What is the time difference between EST and PST?
EST (Eastern Standard Time) is 3 hours ahead of PST (Pacific Standard Time). For example, 12:00 PM EST is 9:00 AM PST. During Daylight Saving Time, EDT is 3 hours ahead of PDT.
What is the time difference between PST and IST?
PST (Pacific Standard Time) is 13.5 hours behind IST (India Standard Time). For example, 12:00 PM PST is 1:30 AM IST the next day.
What is the time difference between EST and GMT?
EST (Eastern Standard Time) is 5 hours behind GMT. For example, 12:00 PM EST is 5:00 PM GMT. During Daylight Saving Time, EDT is 4 hours behind GMT.
What is the time difference between PST and JST?
PST (Pacific Standard Time) is 17 hours behind JST (Japan Standard Time). For example, 12:00 PM PST is 5:00 AM JST the next day.
What is Daylight Saving Time (DST)?
Daylight Saving Time is the practice of advancing clocks during warmer months so that darkness falls later. Most of the US, Canada, and Europe observe DST, while many other countries do not.
When does DST start and end?
In the US and Canada, DST starts on the second Sunday in March and ends on the first Sunday in November. In Europe, it starts on the last Sunday in March and ends on the last Sunday in October.
What time zones does the US have?
The US has nine time zones: Atlantic, Eastern, Central, Mountain, Pacific, Alaska, Hawaii-Aleutian, Samoa, and Chamorro. The contiguous US has four: Eastern, Central, Mountain, and Pacific.
What is the International Date Line?
The International Date Line is an imaginary line on the surface of the Earth that runs from the North Pole to the South Pole and demarcates the change of one calendar day to the next. Crossing it eastward subtracts a day; crossing it westward adds a day.
How many time zones are there in the world?
There are 24 standard time zones, each approximately 15 degrees of longitude apart. However, some time zones have 30- or 45-minute offsets, bringing the total to about 40 time zones.
What time zone is used for scheduling international meetings?
For international meetings, it's common to use UTC or to specify multiple time zones. Tools like this calculator help you find the best meeting time across different regions.
How do I find the best time for a meeting across time zones?
Use the "World Clock" mode to see current times in multiple zones. You can also use the "Time Difference" mode to calculate the offset between two zones and find a time that works for both parties.
What is the time zone for London?
London is in the GMT (Greenwich Mean Time) time zone during winter (UTC+0) and BST (British Summer Time) during summer (UTC+1).
What is the time zone for New York?
New York is in the EST (Eastern Standard Time) zone during winter (UTC-5) and EDT (Eastern Daylight Time) during summer (UTC-4).
What is the time zone for Tokyo?
Tokyo is in the JST (Japan Standard Time) zone, which is UTC+9 year-round. Japan does not observe Daylight Saving Time.
What is the time zone for Sydney?
Sydney is in the AEST (Australian Eastern Standard Time) zone during winter (UTC+10) and AEDT (Australian Eastern Daylight Time) during summer (UTC+11).
How accurate is this time zone calculator?
This calculator provides accurate time zone conversions based on standard UTC offsets. However, DST rules can change, and some regions may have unique time zone rules. Always double-check for critical scheduling.