Time zones: a practical guide
From UTC offsets to IANA zone names, this guide explains what you need to schedule accurately across countries.
Offset vs time zone
An offset such as UTC+2 says how far a clock is from UTC at one instant. A named time zone such as Europe/Berlin contains rules that can change the offset during the year.
Why IANA names matter
When a future date is converted, the zone name lets software apply the rules that belong to that date. This avoids assuming that today’s difference will still apply after a daylight-saving transition.
Countries with multiple zones
Large countries can span several zones. The United States, Canada, Australia, Brazil, Mexico and others therefore need city-level time-zone handling rather than one fixed national offset.
Best workflow
- Choose the exact city or named time zone.
- Use the exact meeting date.
- Check the converted local date as well as the hour.
- Check public holidays and local business hours.