- Japan standard time distribution service over analog telephone lines (Telephone JJY) ends March 31, 2024. (2023/3/15)
- No leap second will be introduced on July 1, 2023. (2023/1/10)
- The way to register using the Hikari-telephone JJY has changed. (2022/9/1)
- "Telephon JJY" service is due to end at the end of March, 2024. (2019/1/28)
- Press Release： World's first use of the "Optical lattice clock" to maintain National standard time.
〜Synchronization with UTC became possible only with the clock of NICT〜（2022/6/10）
LF Standard Time and Frequency Transmission Station
Welcome to Japan Standard Time (JST) Group. JST Group plays an important role in the Generation, Comparison, and Dissemination of Japan Standard Time and Frequency standard. Please choose the contents you'd like to use.
|What we do|
|The Information of Standard-time and Frequency-signal Emission (JJY) (The users of radio wave clock see here for more information, please)|
|Time Dissemination Service (NTP,TEL-JJY,Time Business,calibration)|
|FAQs and Data|
Please contact us if you have any questions, comments, corrections, or suggestions.