The most common vocabulary used in Europe are the following:
GMT - Greenwich Mean Time
UTC - Coordinated Universal Time
CET - Central European Time
CEST - Central European Summer Time
Now, let's head to explaining the relations between these terms.
GMT is exactly the same timezone as UTC, while CET is one hour later than GMT and UTC. CEST on the other hand is two hours later than GMT and UTC
GMT = UTC
GMT = CET-1
GMT = CEST-2
CET = GMT+1
CET = UTC+1
CET = CEST-1
CEST = GMT+2
CEST = UTC+2
CEST = CET+1
After these simple equations above, let's move on to more practical use:
"Timezones" are necessary due to the earth being so huge and the sun incapable of shining on every area at the same exact time. Thus, if it's night in Europe, it's day in America. Every country tends to have an own timezone, while some larger countries (like Russia) have multiple ones.
Here's a short list of a few countries:England - GMT.
Ireland - GMT.
France - GMT+1.
Germany - GMT+1.
Austria - GMT+1.
Italy - GMT+1.
Netherlands - GMT+1.
Romania - GMT+2.
Israel - GMT+2.
Now, what does "+1" actually mean? It means that you add to the GMT 1 more hour to receive your time.If it's 18:00 GMT in England and Germany is GMT+1, it means that it's 19:00 in Germany.
Quite logical, isn't it?
As you can see, most european countries in my list seem to reside in GMT+1 - thus for simpler use, CET is used instead of GMT+1 to declare times. (Remember that CET
Everyone should be able to figure out their timezone thanks to google and diverse sites. Also, after reading this, hopefully everyone is capable of figuring out the differences between each country/timezone.
One last important topic, though. We haven't learned about CEST yet, right?
As the name implies, this time is used in summer. All countries residing in CET become CEST instead. What does this mean?
All countries add +1 to their GMT.
This is what happens to countries during summer:England - GMT+1.
Ireland - GMT+1.
France - GMT+2.
Germany - GMT+2.
Austria - GMT+2.
Italy - GMT+2.
Netherlands - GMT+2.
Romania - GMT+3.
Israel - GMT+3.
CET still means GMT+1, but take note that all countries that formerly were in the CET range during winter, lost their position during summer and became CEST instead.
If you notice any mistakes, please mention them in due time.
It's a very confusing topic.
The most useful site on timezone matters; shows GMT as default time, but anything you could ever need or want to know can be found there as well.