From Nov. 1 to 3, "2005 Nationwide Symposium on Time and Frequency" was held in Xi'an, hosted byTime Service and Time Committee of GPS Technology Application Association in China, Time-frequency Committee of Chinese Astronomical Society, Time-frequency Committee of China Metrological Measuring Institute as well as Measuring and Testing Committee of Chinese Society of Astronautics jointly, undertook by by the National Time Service Center of Chinese Academy of Sciences.

More than 150 experts and scholars from the field of time and frequency all over the country attended the conference, at which 83 papers had been received in total, and in-depth discussion and exchanges was conducted on related issues such as time and frequency standard, time-keeping time transfer, time service, time service for satellite navigation, etc. between the experts participating in the 3-day academic conference.

As a biyearly grand assembly for academic exchanges in time-frequency field of China co-sponsored by the four time-frequencycommittees, the "Nationwide Time and Frequency Symposium" plays a very important role in advancing the cooperation and exchange between time-frequency research units, and promoting the development of time-frequency field in China.