Time Zones Explained
A time zone is a set of rules used to determine local civil time for a geographic region. Real-world timekeeping includes whole-hour, half-hour and quarter-hour offsets, countries with several zones and regional rules that can change.
UTC offsets
A UTC offset shows how far a local clock is ahead of or behind Coordinated Universal Time. An offset describes the difference at a particular moment, but does not contain every rule of a regional time zone.
Named time zones
Software commonly uses IANA identifiers such as Europe/Amsterdam, America/New_York and Asia/Tokyo. A named zone can account for regional rules, including daylight-saving transitions.
One country, several local times
Some countries use more than one time zone. Search for a country on World Clock to display live local times for multiple cities. The selected 12-hour or 24-hour format is applied consistently to all results.
Compare a city with your local time
When you select a city, World Clock shows its live local time and the difference from your device time. This helps with travel, international calls and events across time zones.