The Signals are dependant on atomic clocks and synchronised with the worldwide program of clocks that help Coordinated Universal Time. India's time zone is based over the 82.five°E meridian, which passes by way of Mirzapur. The half-hour offset was decided on to help keep the time near to the mean https://connerziolm.wannawiki.com/1479787/little_known_facts_about_ist_time