<P> Features of the Time and Frequency Standards Laboratory include: </P> <Ul> <Li> High frequency broadcast service operating at 10 MHz under call sign ATA to synchronise the user clock within a millisecond; </Li> <Li> Indian National Satellite System satellite - based standard time and frequency broadcast service, which offers IST correct to ± 10 microsecond and frequency calibration of up to ± 10; and </Li> <Li> Time and frequency calibrations made with the help of pico - and nanoseconds time interval frequency counters and phase recorders . </Li> </Ul> <Li> High frequency broadcast service operating at 10 MHz under call sign ATA to synchronise the user clock within a millisecond; </Li> <Li> Indian National Satellite System satellite - based standard time and frequency broadcast service, which offers IST correct to ± 10 microsecond and frequency calibration of up to ± 10; and </Li>

What is meant by indian standard time why do we need it