Experiences of leap second adjustment operations and questionnaires in Japan

National Institute of Information and Communications Technology (NICT) in Japan has responsibilities to generate and to maintain Japan Standard Time (JST), and to disseminate the JST throughout the country. For these purposes, NICT is operating multiple sets of Cesium frequency standard systems and Hydrogen maser systems to generate stable and reliable time scale. JST is generated and maintained from the ensemble of the signals from these frequency standards. NICT operates the satellite communication link for TWSTFT (Two-Way Satellite Time and Frequency Transfer) link between Asian region and Physikalisch-Technische Bundesanstalt (PTB) in Germany through the collaborations with the National Metrological Institutes in the Asian region to contribute clock data in the region to establish Coordinated Universal Time (UTC). NICT is also participating in the GNSS (Global Navigation Satellite Systems) time link network and both TWSTFT and GNSS data are used for UTC establishment.