Guide to Global Time Zones, UTC Offsets, and Daylight Saving Time (DST)
How are global timezones defined?
The Earth is divided into 24 standard theoretical timezones of 15 degrees longitude each, using Coordinated Universal Time (UTC) as baseline. Each timezone adds or subtracts hours relative to UTC.
The IANA Standard and Daylight Saving Time (DST)
The world clock uses the official IANA timezone database identifiers (e.g. Europe/Madrid, America/New_York). This guarantees mathematical precision when adjusting for daylight saving and standard time transitions across all regions.
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