Explain standard time.

1. In order to maintain uniformity of time as far as possible within the territorial limits of a country, the time at central meridian of the country is taken as the standard meridian and its local time is taken as the standard time for the whole country.
2. The standard meridian is selected in a manner that it is divisible by 15° or by 7°.30’ so that the difference between its standard time and Greenwich mean time may be expressed as multiples of an hour or half an hour.