Time Zones — UTC Offsets and Abbreviations
Look up a time-zone abbreviation, compare city clocks, or convert an appointment. Understand the offset before you send the invitation.
Compare, convert, or look it up
Check the time now, convert a future appointment, or understand the label on an invitation.
Check a clock or current time
- World Clock
Compare live current times across major cities.
- Current Time
Use a simpler live local clock when the task is only your current time.
- United States Clock
See multiple US time zones on one country page.
Convert and schedule
- Timezone Converter
Convert a date and time between two zones with DST-aware logic.
- Meeting Planner
Find overlap windows across multiple regions.
Look up an abbreviation or offset
- UTC
UTC is the neutral global reference used behind timestamps, logs, APIs, and cross-border scheduling.
- GMT
GMT is the historical mean-solar reference associated with Greenwich and still used as a common comparison point.
- EST
EST is the standard-time abbreviation for the eastern part of the United States and Canada outside the daylight-saving period.
- CST
CST in the United States is the standard-time abbreviation for the central zone anchored by cities such as Chicago and Dallas.
- PST
PST is the standard-time abbreviation for the Pacific zone in the western United States and Canada.
- CET
CET is the standard winter-time label used across much of mainland western and central Europe.
Read an offset without guessing
UTC+05:30 means five hours and thirty minutes ahead of UTC. Subtract that offset to find UTC: 18:00 at UTC+05:30 is 12:30 UTC. Then add the destination offset. If you cross midnight, change the calendar date as well as the clock time.
A city is safer than an abbreviation
CST can mean Central Standard Time in North America or China Standard Time. IST is used for different standards in India, Ireland, and Israel. Even an unambiguous standard-time abbreviation may be wrong for a city during daylight saving. Use the city in the converter, then share the result with its date and numeric offset.
Recurring meetings need another check
A weekly 09:00 meeting in one city can shift for a colleague when only one region changes its clocks. Save the organizing city’s time zone in your calendar invitation. Check the weeks around seasonal changes and agree whether the organizer’s local time or a fixed UTC time should stay constant.
The clocks use the time-zone rules installed in your browser. Governments can change those rules, so keeping your browser and operating system updated matters. See the IANA Time Zone Database for how those rules are maintained.