In case of ISRO, timings are sent via satellite. Banks like SBI also subscribe to NPL services as high precision timing is required during forex transactions.The CSIR, which comes under the Ministry of Science and Technology, plans to have 18 atomic clocks, a norm followed by all developed countries to maintain accuracy. Since several parts of north India fall under seismic zones, it also plans to develop a laboratory in south India. "At present, we have five atomic clocks and we will get five more by the end of the year. But this is not enough considering the growing demand for accurate timings by subscribers for which we need to maintain quality.

Source: Economic Times February 19, 2017 03:45 UTC