Page 2 - Lesson Notes
P. 2

2


               meridian of a country as the standard time for the country for uniformity.


                     In India, the longitude of 82° E (82° 30' E) is treated as the standard
                     meridian and the local time at this meridian is considered as the
                     standard time for the whole country. It is known as the Indian Standard
                       Time (IST).
                     Similarly some countries have adopted more than one standard time
                       due to their great longitudinal extent. For example, in Russia, there are
                     as many as eleven standard times.
                     The earth has been divided into twenty-four time zones of one hour
                       each. Each zone thus covers 15° of longitude.
   1   2