# Travel >> Travel Preparation >> Travel Planning

How to Calculate World Time Zone Differences

In order to calculate the time differences between world time zones, you need to use a time zone map. A time zone map shows the hour difference between a given location and Greenwich Mean Time. Given the time in your current location, you then use these differentials to calculate the difference between two respective time zones. Using this technique, you can quickly determine what time it is anywhere in the world.

Time zone map

Instructions

- 1
  Open a time zone map (See Resources).
- 2
  Find your location on the map and also find the location for which you want to know the time difference. For example, you are in Buffalo, New York and want to know the time in Munich, Germany.
- 3
  Count the hour difference between the two locations on the map. In the example, Buffalo is GMT -5, and Munich is GMT +1, so the difference is six hours.
- 4
  Add or subtract the difference in time periods. In the example, if it is 10 AM in Buffalo, then 10 AM plus 6 hours equals 4 PM in Munich. You need to add the time if the location is east on the time zone map. You need to subtract the time if the location is west on the time zone map.