Time Zones - Different time zones of the world

  Zone                            Offset   Where 

  ----                            ------   ------

   EET     Eastern European        +2      Finland, Eastern Europe

   CET     Central European        +1      Western Europe, Sweden

   GMT     Greenwich Mean          none    United Kingdom, Portugal

   AST     Atlantic Standard       -4      Halifax

   EST     Eastern Standard        -5      NY, DC, Toronto, Montreal

   CST     Central Standard        -6      Chicago, Houston, Winnipeg

   MST     Mountain Standard       -7      Denver, Calgary, Edmonton  

   PST     Pacific Standard        -8      LA, San Fransisco, Vancouver

Daylight Savings Time (DST)
Different countries have different dates for Daylight Savings Time.
In most of Europe, DST dates 1994 are March 27 - Oct 25. DST
adjustment is +1 hour.

   An event is supposed to occur at 23:00 CET and your timezone is EST:

                           -->     23.00 CET

   CET offset      +1      -->     22.00 GMT

   EST offset      -5      -->     17.00 EST

                           -->      5 pm EST

   An event is supposed to occur at 1 pm MST and timezone is EET DST:

                           -->      1 pm MST

                           -->     13.00 MST

   MST offset      -7      -->     20.00 GMT

   EET offset      +2      -->     22.00 EET

   DST adjustment  +1      -->     23.00 EET DST

Given offset is subtracted from the local time to get GMT and added to GMT to get the time for a specific zone.

Here is a colourmap of the timezones in the world.