the international date line

THE INTERNATIONAL DATE LINE;
The IDL is an imaginary line on the surface of the earth opposite the prime meridian o degree where the date changes as one travels east or west acrossit.Roughly aliong 180 degree longitude with diversions to pass around some territories and land groups it mostly correspound to the time zone boundary separating -12 and + 12 hours coordinateduniverrsal time  UTC greenwich mean time GMT crossing The IDL traveling east resultsin a day or 24 hours being substracted so traveler repeats the date and crossing west result in a day being added.The line is necessary in orderto have a fixed boundary  on the globe where the calendar date resets.
GREENWICH MEAN TIME GMT;
The local time at greenwich londin located on the prime meridian 0 degree longitude from which the standard times of different areas of the globe are calculated 15 degree longitude representing one hour in time.
REGION;
GEOGRAPHICAL REGION OR GEOGRAPHICAL ZONE;
A fairly homogeneous geographical area is called geographical zone  or region.In geography regions can be broadly divided by physical chracteristics physicalregion human impact chracteristics cultural region and the interaction of the people and the enviroment enviromental region.There are five major regions of the earth divided on the basis of latitudes.The difference between them relate to climate and the behaviour of the sun....