The Alerts are based upon atomic clocks and synchronised with the worldwide process of clocks that assistance Coordinated Common Time. India's time zone is predicated to the eighty two.five°E meridian, which passes by Mirzapur. The 50 %-hour offset was picked to maintain the time close to the mean solar time https://ist-world-clock86799.wikigop.com/442992/the_5_second_trick_for_live_world_clock