Let's talk about time zones. So do we ever think why is time zone different for different countries, what are the factors that make time zone different in different regions or countries? Why it is not the same across the globe. OK, don't get confused you will get all your answers in this article.
A time zone is a region or an area in our earth that has the same time for all places in that region. Earth is divided into 24 regions according to time zones. In one time zone area time will be the same for each place in that area.
Time zone is determined by the longitude (in degrees) of an area. Dividing the longitude by 15 will give the accurate time zone of that area. For example, the longitude of an area is 45 degrees East then the timezone will be 45/15 = +3 i.e. GMT+3.00 or UTC+3.00. If the longitude is 45 degree west then time zone will be -(45/15) = -3 i.e. GMT-3.00 or UTC -3.00. Now another question comes that what is longitude and how it is determined.
Longitude: Longitude is a geographical coordinate that determines the east-west position of a point on the earth's surface.
Latitude: Latitude is a geographical coordinate that determines the north-south position or a point in the earth's surface.
So as we have seen time zone depends on the longitude of a specific area. However different countries are free to determine time zones in their country.