TOOLBOX
Worldwide synchronisation:
Time zones
How to express timing in a way that can be understood everywhere in the world?
This manual is only a simplified guide for cases when you need to work quickly and without long philosophising with time data on a global worldwide scale.
Our planet has 24 time zones. The primary reference point for all the world's clocks is Greenwich, London, whose position is the zero meridian (0° longitude). When it is midnight in London, it is midday on the opposite side of the Earth. It follows that if we want to time an event to exactly the same moment, we need to give not only the hour, minute, second, etc·, but also the corresponding place. For example, if a rocket takes off in the afternoon at five o'clock Houston time (Texas, USA), in Paris (France, EU) they will already have a night - in vain would they turn on their TVs at five o'clock Paris time.
Calculations of times between distant locations are very easy if we choose the worldwide common reference time as our private reference time - i·e· London time at the point of Greenwich. This is called Greenwich Mean Time, abbreviated GMT. Do the conversion in your head, or use one of the web time calculators below.
Below are quick automatic FREE web tools for immediate use (quite intuitive to understand even without language or science skills):