Introduction
Calculating timezone differences might seem complicated, but with the right method it's very simple. In this guide, you'll learn the most practical technique.
Understanding Timezones
The world is divided into 24 main time zones, each representing 1 hour. The Greenwich meridian (UTC 0) is the reference point.
- Positive Zones: East of Greenwich (more advanced)
- Negative Zones: West of Greenwich (more behind)
Practical Method
Step 1: Identify the UTC of both locations
Step 2: Subtract the smaller UTC from the larger
Step 3: The result is the difference in hours
Example:
São Paulo (UTC-3) and London (UTC+0)
Difference: 0 - (-3) = 3 hours
London is 3 hours ahead of São Paulo.
Extra Tip: Daylight Saving Time
Some countries change their time zones in summer. Brazil doesn't anymore (since 2019), but USA and Europe do. Always check dates!
Conclusion
Practice a few times and you'll quickly memorize the main zones: NYC (-5), London (0), Tokyo (+9), Sydney (+10).