What is a Time Zone?

UTC - (Coordinated Universal Time, Temps Universel Coordonné)

The international time standard (formerly Greenwich Mean Time, or GMT). Zero hours UTC is midnight in Greenwich, England, which is located at 0 degrees longitude. Everything east of Greenwich (up to 180 degrees) is later in time (+); everything west is earlier (-).

Therefore, your time zone is the number of hours away from Greenwich, England. The Asian and Oceania Continents, and some countries of Europe and Africa are ahead of Greenwich (+) while the American continent and some countries in Africa are behind Greenwich (-). Some countries in Europe and Africa are UTC.