± 1 0 − 1 0 ; ▁and ▁Time ▁and ▁frequency ▁cal ibr ations ▁made ▁with ▁the ▁help ▁of ▁p ico - ▁and ▁nan ose cond s ▁time ▁interval ▁frequency ▁coun ters ▁and ▁phase ▁record ers . ▁ ▁I ST ▁is ▁taken ▁as ▁the ▁standard ▁time ▁as ▁it ▁passes ▁through ▁almost ▁the ▁centre ▁of ▁India . ▁To ▁communicate ▁the ▁exact ▁time ▁to ▁the ▁people , ▁the ▁exact ▁time ▁is ▁broadcast ▁over ▁the ▁national ▁All ▁India ▁Radio ▁and ▁Do ord ar sh an ▁television ▁network . ▁Tele phone ▁companies ▁have ▁dedicated ▁phone ▁numbers ▁connected ▁to ▁mirror ▁time ▁servers ▁that ▁also ▁relay ▁the ▁precise ▁time . ▁Another ▁increasing ly ▁popular ▁means ▁of ▁obtain ing ▁the ▁time ▁is ▁through ▁Global ▁Position ing ▁System ▁( G PS ) ▁rece ivers . ▁ ▁See ▁also ▁Bomb ay ▁Time ▁Cal cut ta ▁Time ▁Equ ation ▁of ▁time ▁International ▁At omic ▁Time ▁John ▁Gold ingham ▁Mad ras ▁Time ▁Port ▁Bla ir ▁mean ▁time ▁P unct ual ity ▁Railway ▁time ▁in ▁India ▁Sri ▁L anka ▁Standard ▁Time ▁Terr est rial ▁Time ▁Time ▁in ▁Afghan istan ▁Time ▁in ▁India ▁Time ▁in ▁Sri ▁L anka ▁Time ▁zone ▁( lists ) ▁UTC + 0 5 : 3 0 ▁Zone info ▁ ▁References ▁ ▁External ▁links ▁National ▁Phys ical ▁Labor atory ▁E valu ating ▁two ▁time z ones ▁and ▁Day light ▁S aving ▁Time ▁for ▁India , ▁by ▁Vir al ▁Shah ▁& ▁Vik ram ▁A gg ar wal . ▁ ▁Category : Time ▁in ▁India ▁Category : Ge ography ▁of ▁India ▁Category : Time ▁zones