Question

How is the standard time of a place determined?

Answer 1

By its longitudinal and latitudinal extension and the longitude and latitude which pass through the place.

It is determined with the help of IDL which stands for International Date Line.

You need to use a time zone database.

You could also use a time zone map, but many don’t show what places use daylight saving time, and those that do don’t show when it is in effect.

Answer 2

by longitudinal division